DS2155 and DS26401 Software Comparison

Abstract

Application Note 403 describes the software considerations when migrating an existing design based on the DS2155 T1/E1/J1 single chip transceiver (SCT) to the DS26401 T1/E1/J1 octal framer. In comparison, the Dallas Semiconductor DS26401 octal framer uses a completely revised architecture, contains eight independent framers, and the device package is only 50% larger in area than the DS2155. While the DS2155 does include an integrated line interface unit (LIU), the DS26401 will seamlessly interface will all Dallas Semiconductor T1/E1/J1 LIU devices. Any designer who is thinking of migrating an existing design to use the DS26401 should read this application note. The application note contains detailed information for software migration such as: register location changes, how individual functions have changed from the DS2155 to the DS26401, and which new functions are available on the DS26401. In the end, the designer should have enough information to easily migrate an existing design to the DS26401.

Introduction

This application note describes the differences between the DS2155 and the DS26401. The DS2155 contains both a line interface unit (LIU) and a T1/E1 framer, while the DS26401 is only a T1/E1 framer. Therefore, none of the LIU functions are present in the DS26401.

While the DS2155 is available in 1-port and 4-port devices, the DS26401 is an 8-port device. Each port in these devices is programmed and operates independently of the others.

Indirect Registers

The DS2155 uses indirect registers for the following "per-channel" functions. The DS26401 uses direct registers for these functions. The only use of indirect registers in the DS26401 is for loading repetitive patterns, up to 512 bytes, in the BERT.

DS2155
Indirect Register Function
DS26401
Direct Register
Comments
Per-Channel Transmit Idle Code TIDR1 to TIDR24
Per-Channel Receive Idle Code RIDR1 to RIDR24
Bert Transmit Channel Select TBCS1 to TBCS4
Transmit Fractional Channel Select TGCCS1 to TGCCS4
Payload Error Insert Channel Select Not Supported
Transmit Hardware Signaling Channel Select SSIE1 to SSIE4
Bert Receive Channel Select RBCS1 to RBCS4
Receive Fractional Channel Select RGCCS1 to RGCCS4
Receive Signaling Reinsertion Channel Select RSI1 to RSI4
Receive Signaling All-Ones Insertion Channel Select RSAOI1 to RSAOI3 T1 Mode Only

Terminology

Some terminology in the DS26401 data sheet is different from previous T1/E1 data sheets from Dallas Semiconductor. As an example, previous data sheets used the acronym RLOS to refer to receive loss of sync. In the DS26401 data sheet RLOS more correctly refers to receive loss of signal. The table below shows the differences.

Condition DS26401 Data Sheet Previous Data Sheets
Loss of In-Bound Signal RLOS (Receive Loss Of Signal) RCL (Receive Carrier Loss)
Loss of Synchronization RLOF (Receive Loss Of Framing) RLOS (Receive Loss Of Synchronization)
In-Bound All Ones AIS (Alarm Indication Signal)
T1 and E1 Modes
AIS for E1 Mode; Blue Alarm for T1 Mode
Remote Alarm RAI (Remote Alarm Indication)
T1 and E1 Modes
RAI for E1 Mode; Yellow Alarm for T1 Mode

Register Mapping

For each of the 8 ports in the DS26401, most of the functions are independently programmed. Therefore, there are eight separate but identical registers for each port. In the following tables only the base address is shown for each register. The full address for each port is found by the following.

Base Address + (0x200 × n), where n = 0 to 7 for Ports 1 through 8

The only functions that are shared by all 8 ports are the Global and BERT Functions. The Global Function registers are GCR1, GCR2, GSR1, GSR2 and the IDR register. All addresses are shown in hexadecimal.


Direct Register Mapping


The following registers in the DS2155 can be mapped directly to registers in the DS26401.

DS2155 DS26401 DS2155 Register Description
Address Name Address Name
08 SSIE1 118 SSIE1 Software Signaling Insertion Enable 1
09 SSIE2 119 SSIE2 Software Signaling Insertion Enable 2
0A SSIE3 120 SSIE3 Software Signaling Insertion Enable 3
0B SSIE4 121 SSIE4 Software Signaling Insertion Enable 4
0C T1RDMR1 03C RDMWE1 T1 Receive Digital Milliwatt Enable Register 1
0D T1RDMR2 03D RDMWE2 T1 Receive Digital Milliwatt Enable Register 2
0E T1RDMR3 03E RDMWE3 T1 Receive Digital Milliwatt Enable Register 3
0F IDR 0F8 IDR Device Identification Register
38 RSINFO1 098 RSS1 Receive Signaling Change of State Information 1
39 RSINFO2 099 RSS2 Receive Signaling Change of State Information 2
3A RSINFO3 09A RSS3 Receive Signaling Change of State Information 3
3B RSINFO4 09B RSS4 Receive Signaling Change of State Information 4
3C RSCSE1 0A8 RSCSE1 Receive Signaling Change of State Interrupt Enable 1
3D RSCSE2 0A9 RSCSE2 Receive Signaling Change of State Interrupt Enable 2
3E RSCSE3 0AA RSCSE3 Receive Signaling Change of State Interrupt Enable 3
3F RSCSE4 0AB RSCSE4 Receive Signaling Change of State Interrupt Enable 4
42 LCVCR1 050 LCVCR1 Line Code Violation Count Register 1
43 LCVCR2 051 LCVCR2 Line Code Violation Count Register 2
44 PCVCR1 052 PCVCR1 Path Code Violation Count Register 1
45 PCVCR2 053 PCVCR2 Path Code Violation Count Register 2
46 FOSCR1 054 FOSCR1 Frames Out-of-Sync Count Register 1
47 FOSCR2 055 FOSCR2 Frames Out-of-Sync Count Register 2
48 EBCR1 056 EBCR1 E-Bit Count Register 1
49 EBCR2 057 EBCR2 E-Bit Count Register 2
4B PCLR1 1D0 PCL1 Per-Channel Loopback Enable Register 1
4C PCLR2 1D1 PCL2 Per-Channel Loopback Enable Register 2
4D PCLR3 1D2 PCL3 Per-Channel Loopback Enable Register 3
4E PCLR4 1D3 PCL4 Per-Channel Loopback Enable Register 4
50 TS1 140 TS1 Transmit Signaling Register 1
51 TS2 141 TS2 Transmit Signaling Register 2
52 TS3 142 TS3 Transmit Signaling Register 3
53 TS4 142 TS4 Transmit Signaling Register 4
54 TS5 144 TS5 Transmit Signaling Register 5
55 TS6 145 TS6 Transmit Signaling Register 6
56 TS7 146 TS7 Transmit Signaling Register 7
57 TS8 147 TS8 Transmit Signaling Register 8
58 TS9 148 TS9 Transmit Signaling Register 9
59 TS10 149 TS10 Transmit Signaling Register 10
5A TS11 14A TS11 Transmit Signaling Register 11
5B TS12 14B TS12 Transmit Signaling Register 12
5C TS13 14C TS13 Transmit Signaling Register 13
5D TS14 14D TS14 Transmit Signaling Register 14
5E TS15 14E TS15 Transmit Signaling Register 15
5F TS16 14F TS16 Transmit Signaling Register 16
60 RS1 040 RS1 Receive Signaling Register 1
61 RS2 041 RS2 Receive Signaling Register 2
62 RS3 042 RS3 Receive Signaling Register 3
63 RS4 043 RS4 Receive Signaling Register 4
64 RS5 044 RS5 Receive Signaling Register 5
65 RS6 045 RS6 Receive Signaling Register 6
66 RS7 046 RS7 Receive Signaling Register 7
67 RS8 047 RS8 Receive Signaling Register 8
68 RS9 048 RS9 Receive Signaling Register 9
69 RS10 049 RS10 Receive Signaling Register 10
6A RS11 04A RS11 Receive Signaling Register 11
6B RS12 04B RS12 Receive Signaling Register 12
6C RS13 04C RS13 Receive Signaling Register 13
6D RS14 04D RS14 Receive Signaling Register 14
6E RS15 04E RS15 Receive Signaling Register 15
6F RS16 04F RS16 Receive Signaling Register 16
74 TDS0SEL 189 TDS0SEL Transmit Channel Monitor Select
75 TDS0M 1BB TDS0M Transmit DS0 Monitor Register
76 RDS0SEL 012 RDS0SEL Receive Channel Monitor Select
77 RDS0M 060 RDS0M Receive DS0 Monitor Register
80 TCICE1 150 TCICE1 Transmit Idle Code Enable Register 1
81 TCICE2 151 TCICE2 Transmit Idle Code Enable Register 2
82 TCICE3 152 TCICE3 Transmit Idle Code Enable Register 3
83 TCICE4 153 TCICE4 Transmit Idle Code Enable Register 4
84 RCICE1 0D0 RCICE1 Receive Idle Code Enable Register 1
85 RCICE2 0D1 RCICE2 Receive Idle Code Enable Register 2
86 RCICE3 0D2 RCICE3 Receive Idle Code Enable Register 3
87 RCICE4 0D3 RCICE4 Receive Idle Code Enable Register 4
88 RCBR1 0C4 RCBR1 Receive Channel Blocking Register 1
89 RCBR2 0C5 RCBR2 Receive Channel Blocking Register 2
8A RCBR3 0C6 RCBR3 Receive Channel Blocking Register 3
8B RCBR4 0C7 RCBR4 Receive Channel Blocking Register 4
8C TCBR1 1C4 TCBR1 Transmit Channel Blocking Register 1
8D TCBR2 1C5 TCBR2 Transmit Channel Blocking Register 2
8E TCBR3 1C6 TCBR3 Transmit Channel Blocking Register 3
8F TCBR4 1C7 TCBR4 Transmit Channel Blocking Register 4
B7 TCD1 1AC TCD1 Transmit Code Definition Register 1
B8 TCD2 1AD TCD2 Transmit Code Definition Register 2
B9 RUPCD1 0AC RUPCD1 Receive Up Code Definition Register 1
BA RUPCD2 0AD RUPCD2 Receive Up Code Definition Register 2
BB RDNCD1 0AE RDNCD1 Receive Down Code Definition Register 1
BC RDNCD2 0AF RDNCD2 Receive Down Code Definition Register 2
BE RSCD1 09C RSPCD1 Receive Spare Code Definition Register 1
BF RSCD2 09D RSPCD2 Receive Spare Code Definition Register 2
C0 RFDL 062 RFDL Receive FDL Register
C1 TFDL 162 TFDL Transmit FDL Register
C6 RSF 064 RAF Receive Align Frame Register
C7 RNAF 065 RNAF Receive Nonalign Frame Register
C8 RSiAF 066 RSiAF Receive Si Align Frame
C9 RSiNAF 067 RSiNAF Receive Si Nonalign Frame
CA RRA 068 RRA Receive Remote Alarm Bits
CB RSa4 069 RSa4 Receive Sa4 Bits
CC RSa5 06A RSa5 Receive Sa5 Bits
CD RSa6 06B RSa6 Receive Sa6 Bits
CE RSa7 06C RSa7 Receive Sa7 Bits
CD RSa8 06D RSa8 Receive Sa8 Bits
D0 TAF 164 TAF Transmit Align Frame Register
D1 TNAF 165 TNAF Transmit Nonalign Frame Register
D2 TSiAF 166 TSiAF Transmit Si Align Frame
D3 TSiNAF 167 TSiNAF Transmit Si Nonalign Frame
D4 TRA 168 TRA Transmit Remote Alarm Bits
D5 TSa4 169 TSa4 Transmit Sa4 Bits
D6 TSa5 16A TSa5 Transmit Sa5 Bits
D7 TSa6 16B TSa6 Transmit Sa6 Bits
D8 TSa7 16C TSa7 Transmit Sa7 Bits
D9 TSa8 16D TSa8 Transmit Sa8 Bits
DA TSACR 114 TSACR Transmit Sa Bit Control Register
NS = not supported

Bit-Level Mapping


Although the following DS2155 registers do not have direct mappings to registers in the DS26401, this table shows how to map the individual bits of the DS2155 registers into the individual bit in the DS26401 registers.

DS2155 DS26401 BIT LOCATION; 2155 BIT = 26401 REG. BIT COMMENTS
ADDRESS NAME FUNCTION
00 MSTRREG Master Mode Register 0 = RMMR.1 & TMMR.1
1 = RMMR.0 & TMMR.0
2 =
3 =
4 =
5 =
6 =
7 =
01 IOCR1 I/O Configuration Register 1 0 = TCR3.7
1 = TIOCR.2
2 = TIOCR.0
3 = TIOCR.1
4 = RIOCR.2
5 = RIOCR.0
6 = RIOCR.1
7 = RIOCR.3
02 IOCR2 I/O Configuration Register 2 0 = RIOCR.4
1 = TIOCR.4
2 = RIOCR.5
3 = TIOCR.5
4 = TIOCR.4
5 = RIOCR.6
6 = TIOCR.7
7 = RIOCR.7
03 T1RCR1 T1 Receive Control Register 1 0 = RCR1.0
1 = RCR1.1
2 = RCR1.7
3 = RCR1.3
4 = RCR2.2
5 = RCR2.3
6 = RCR1.4
7 =
04 T1RCR2 T1 Receive Control Register 2 0 = RCR2.0
1 = RCR1.2
2 = NS *
3 = NS **
4 = RCR2.4
5 = RCR1.6
6 = RCR1.5
7 =
* ZBTSI not supported in the DS26401

** Information available in the HDLC section

05 T1TCR1 T1 Transmit Control Register 1 0 = TCR1.0
1 = TCR1.1
2 = TCR2.7
3 = TCR1.3
4 = TCR1.4
5 = TCR1.5
6 = TCR1.6
7 = TCR1.7
06 T1TCR2 T1 Transmit Control Register 2 0 = TCR2.0
1 = NS *
2 = TCR2.2
3 = TCR2.3
4 = TCR2.4
5 = NS **
6 = TCR2.6
7 = TCR1.2
* ZBTSI not supported in the DS26401
Information available in the HDLC section
07 T1CCR1 T1 Common Control Register 1 0 = TCR3.0
1 = TCR2.1
2 = TCR3.2
3 = TCR4.2
4 = TCR4.3
5 =
6 =
7 =
10 INFO1 Information Register 1 0 = RLS2.0 *
1 = RLS2.1 *
2 = RLS2.2 *
3 = RLS2.3 *
4 = RLS2.4 *
5 = RLS2.5 *
6 = TLS1.3 *
7 = RLS2.7 *
* T1 Mode Only
11 INFO2 Information Register 2 0 = NS *
1 = NS *
2 = NS *
3 = NS *
4 = NS *
5 = NS *
6 = NS **
7 = BER.0 ***
* LIU functions are not supported
** Specific BOC function not supported
*** Information available in BERT section
12 INFO3 Information Register 3 0 = RLS2.5 *
1 = RLS2.4 *
2 = RLS2.6 *
3 =
4 =
5 =
6 =
7 =
* E1 Mode Only
13 UNUSED
14 IIR1 Interrupt Information Register 1 Contact RIIR and TIIR DS26401 registers
15 IIR2 Interrupt Information Register 2 Contact RIIR and TIIR DS26401 registers
16 SR1 Status Register 1 0 = NS *
1 = NS *
2 = NS *
3 = NS *
4 = NS *
5 = RLS4.3
6 = RLS4.1
7 = NS *
* LIU functions are not supported
17 IMR1 Interrupt Mask Register 1 0 = NS *
1 = NS *
2 = NS *
3 = NS *
4 = NS *
5 = RIM4.3
6 = RIM4.1
7 = NS *
* LIU functions are not supported
18 SR2 Status Register 2 0 = RLS1.0 *
1 = RLS1.1 **
2 = RLS1.2
3 = RLS1.3 ***
4 = RLS1.4
5 = RLS1.5
6 = RLS1.6
7 = RLS1.7 ***
* The DS2155 data sheet used the acronym RLOS (Receive Loss of Synchronization) to refer to RLOF (Receive Loss of Frame)
** The DS2155 data sheet used the acronym RCL (Receive Carrier Loss) to refer to RLOS (Receive Loss of Signal)
*** T1 Mode Only
19 IMR2 Interrupt Mask Register 2 0 = RIM1.0
1 = RIM1.1
2 = RIM1.2
3 = RIM1.3
4 = RIM1.4
5 = RIM1.5
6 = RIM1.6
7 = RIM1.7
1A SR3 Status Register 3 0 = RLS1.3 *
1 = RLS3.0 **
2 = RLS3.1 **
3 = RLS3.3 **
4 = TLS1.0 **
5 = RLS3.0 **
6 = RLS3.1 **
7 = RLS3.2 **
* E1 Mode Only
** The DS26401 uses separate interrupt clear bits, while the DS2155 uses a double polled interrupt bit
DS26401 interrupt and clear bits
DS26401 Interrupt
RLS3.0
RLS3.1
RLS3.3
TLS1.0
RLS3.0
RLS3.1
RLS3.2
DS26401 Clear
RLS1.7
RLS3.5
RLS3.7
TLS1.1
RLS1.4
RLS1.5
RLS1.6
1B IMR3 Interrupt Mask Register 3 0 = RIM1.0
1 = RIM3.1
2 = RIM3.2
3 = RIM3.3
4 = RIM1.4
5 = RIM3.5
6 = RIM3.6
7 = RIM3.7
1C SR4 Status Register 4 0 = RLS2.0
1 = RLS2.1
2 = RLS4.0
3 = TLS1.3
4 = TLS1.2
5 = RLS2.2
6 = RLS2.3
7 = RLS7.4
1D IMR4 Interrupt Mask Register 4 0 = RIM2.0
1 = RIM2.1
2 = RIM4.0
3 = TIM1.3
4 = TIM1.1
5 = RIM2.2
6 = RIM2.3
7 = RIM7.4
1E SR5 Status Register 5 0 = RLS4.5
1 = RLS4.6
2 = RLS4.7
3 = TLS1.5
4 = TLS1.6
5 = TLS1.7
6 =
7 =
1D IMR5 Interrupt Mask Register 5 0 = RIM2.0
1 = RIM2.1
2 = RIM4.0
3 = TIM1.3
4 = TIM1.2
5 = RIM2.2
6 =
7 =
20 SR6 Status Register 6 Information available in HDLC section
21 IMR6 Interrupt Mask Register 6 Information available in HDLC section
22 SR7 Status Register 7 Information available in HDLC section
23 IMR7 Interrupt Mask Register 7 Information available in HDLC section
24 SR8 Status Register 8 0 = RLS7.0
1 = NS *
2 = TLS2.4
3 = RLS7.2
4 = NS *
5 = RLS7.1
6 =
7 =
25 IMR8 Interrupt Mask Register 8 0 = RIM7.0
1 =
2 = TIM2.4
3 = RIM7.2
4 = TIM1.2
5 = RIM7.1
6 =
7 =
26 SR9 Status Register 9 Information available in BERT section
27 IMR9 Interrupt Mask Register 9 Information available in BERT section
28 PCPR Per-Channel Pointer Register Information is in Indirect Register section
29 PCDR1 Per-Channel Data Register 1 Information is in Indirect Register section
2A PCDR2 Per-Channel Data Register 2 Information is in Indirect Register section
2B PCDR3 Per-Channel Data Register 3 Information is in Indirect Register section
2C PCDR4 Per-Channel Data Register 4 Information is in Indirect Register section
2D INFO4 Information Register 4 Information available in HDLC section
2E INFO5 Information Register 5 Information available in HDLC section
2F INFO6 Information Register 6 Information available in HDLC section
30 INFO7 Information Register 7 0 = RRTS7.2
1 = RRTS7.1
2 = RRTS7.0
3 = RRTS7.3
4 = RRTS7.4
5 = RRTS7.5
6 = RRTS7.6
7 = RRTS7.7
31 H1RC HDLC #1 Receive Control Information available in HDLC section
32 H2RC HDLC #2 Receive Control Unsupported function in the DS26401
33 E1RCR1 E1 Receive Control Register 1 0 = RCR1.0
1 = RCR1.1
2 = RCR1.2
3 = RCR1.3
4 = RCR1.4
5 = RCR1.6
6 = RCR1.5
7 = RCR3.5
34 E1RCR2 E1 Receive Control Register 2 0 = RCR2.0
1 =
2 = NS *
3 = NS *
4 = NS *
5 = NS *
6 = NS *
7 = NS *
* The RLINK and RLCLK functions are not supported on the DS26401
35 E1RCR1 E1 Transmit Control Register 1 0 = TCR1.0
1 = TCR1.5
2 = TCR1.2
3 = TCR1.3
4 = TCR1.4
5 = TCR1.1
6 = TCR1.6
7 = TCR1.7
36 E1TCR2 E1 Transmit Control Register 2 0 = TCR2.5
1 = TCR2.6
2 = TCR2.7
3 = NS *
4 = NS *
5 = NS *
6 = NS *
7 = NS *
* The TLINK and TLCLK functions are not supported on the DS26401
37 BOCC BOC Control Register 0 = THC2.6
1 = RBOCC.1
2 = RBOCC.2
3 = RBOCC.7
4 = NS *
5 =
6 =
7 =
* The DS26401 has a dedicated receieve BOC message register
40 SIGCR Signaling Control Register 0 = RFSA1.4 *
1 =
2 =
3 = RSIGC.2
4 = RSIGC.1
5 =
6 =
7 = NS **
* The DS26401 forces signaling to all ones on a per channel basis using the RSAOI1 - RSAOI4 registers
** THe DS26401 selects signaling re-insertion on a per channel basis using the SRI1 - SRI4 registers
41 ERCNT Error Count Configuration Register 0 = ERCNT.0 *
1 = ERCNT.1
2 = ERCNT.2
3 = ERCNT.0
4 = ERCNT.3
5 = ERCNT.4
6 = ERCNT.5
7 = -
* T1 Mode

** E1 Mode

4A LBCR Loopback Control Register 0 = RCR3.0
1 = RCR3.1
2 = RCR3.2
3 = NS *
4 = NS *
5 = -
6 = -
7 = -
* LIU functions are not supported
4F ESCR Elastic Store Control Register 0 = RESCR.0
1 = RESCR.1
2 = RESCR.2
3 = RESCR.3
4 = TESCR.0
5 = TESCR.1
6 = TESCR.2
7 = TESCR.3
70 CCR1 Common Control Register 1 0 = TCR3.3
1 = TCR3.4
2 = TCR3.5
3 = NS *
4 = TCR3.6
5 = RSIGC.0
6 = TCR3.0
7 = NS *
* The DS26401 does not use Indirect Registers
** LIU functions are not supported
71 CCR2 Common Control Register 2 0 = NS *
1 = GCR2.4
2 = GCR2.5
3 =
4 =
5 =
6 =
7 =
72 CCR3 Common Control Register 3 0 = RESCR.6
1 = RESCR.7
2 = TESCR.6
3 = TESCR.7
4 =
5 =
6 = GCR1.0
7 = NS *
* Unsupported function in the DS26401
73 CCR4 Common Control Register 4 0 = NS *
1 = NS *
2 = NS *
3 = NS *
4 = NS **
5 = NS **
6 = NS **
7 = NS **
* The DS26401 does not have user definable output pins
** LIU functions are not supported
78 LIC1 Line Interface Control 1 Unsupported function in the DS26401
79 LIC2 Line Interface Control 2 Unsupported function in the DS26401
7A LIC3 Line Interface Control 3 Unsupported function in the DS26401
7B LIC4 Line Interface Control 4 Unsupported function in the DS26401
7C UNUSED
7D TLBC Transmit Line Build-Out Control Unsupported function in the DS26401
7E IAAR Idle Array Address Register The DS26401 does not use Direct Registers
7F PCICR Per-Channel Idle Code Value Register The DS26401 does not use Direct Registers
90-9F HDLC1 HDLC #1 Functions Registers Information available in HDLC section
A0-AF HDLC2 HDLC #2 Functions Registers Unsupported function in the DS26401
B0 ESIBCR1 Extended System Information Bus Control Register 1 Unsupported function in the DS26401
B1 ESIBCR2 Extended System Information Bus Control Register 2 Unsupported function in the DS26401
B2 ESIB1 Extended System Information Bus Register 1 Unsupported function in the DS26401
B3 ESIB2 Extended System Information Bus Control Register 1 Unsupported function in the DS26401
B4 ESIB3 Extended System Information Bus Register 3 Unsupported function in the DS26401
B5 ESIB4 Extended System Information Bus Register 4 Unsupported function in the DS26401
B6 IBCC In-Band Code Control Register 0 = RIBCC.0
1 = RIBCC.1
2 = RIBCC.2
3 = RIBCC.3
4 = RIBCC.4
5 = RIBCC.5
6 = TCR4.0
7 = TCR4.1
BD RSCC In-Band Receive Spare Control Register 0 = RSCC.0
1 = RSCC.1
2 = RSCC.2
3 =
4 =
5 =
6 =
7 =
C2 RFDLM1 Receive FDL Match Register 1 Unsupported Function in the DS26401
C3 RFDLM2 Receive FDL Match Register 2 Unsupported Function in the DS26401
C4 Unused Unused
C5 IBOC Interleave Bus Operation Control Register The DS26401 Interleave Bus Operation function has separate receive and transmit control registers
DS26401 Address
084
188
Function
Receive IBO Control
Transmit IBO Control
DB-E1 BERT BERT Functions Registers Information available in BERT section
E2 Unused Unused
E3-EF BERT BERT Functions Registers Information available in BERT section
F0-FF TEST Test Register Unsupported function in the DS26401

HDLC Controller

The DS26401 has a single HDLC controller that may be mapped to any time slot or to the FDL (T1 mode) or any combinations of Sa bits (E1 mode). The table below list the differences between the DS2155's and the DS26401's HDLC function.

FUNCTION DS2155 DS26401
Number of Controllers 2 1
FIFO Size 128 bytes 64 bytes
Channel Assignment Any combination of channels;
Facilities Data Link bit stream;
Any combination of Sa bits
Any single DS0;
Facilities Data Link bit stream;
Any combination of Sa bits
SS7 Support Yes No
DS2155 DS26401 BIT LOCATION;
2155 BIT = 26401 REG. BIT
COMMENTS
ADDRESS NAME FUNCTION
31 H1RC HDLC #1 Receive Control 0 = NS *
1 =
2 =
3 =
4 =
5 =
6 = RHC1.5
7 = RHC1.6
* The DS26401 does not have support for Signaling System 7 (SS7)
32 H2RC HDLC #2 Receive Control Unsupported function in the DS26401
90 H2RC HDLC #2 Receive Control 0 = THC1.0
1 = THC1.1
2 = THC1.2
3 = THC1.3
4 = THC1.4
5 = THC1.5
6 = THC1.6
7 = THC1.7
91 H1FC HDLC #1 FIFO Control 0 = RHFC.0
1 = RHFC.1
2 = NS *
3 = THFC.0
4 = THFC.1
5 = NS *
6 =
7 =
* The HDLC FIFO is only 64 bytes deep on the DS26401
92 H1RCS1 HDLC #1 Receive Channel Select 1 The DS26401 uses the RHC register to select the channel to receive HDLC data
The DS26401 can only receive HDLC data in a single DSO channel
93 H1RCS2 HDLC #2 Receive Channel Select 2
94 H1RCS3 HDLC #2 Receive Channel Select 3
95 H1RCS4 HDLC #2 Receive Channel Select 4
96 H1RTSBS HDLC #1 Receive Time Slot Bits/Sa Bits Select
97 H1TCS1 HDLC #1 Transmit Channel Select 1 The DS26401 uses the THC2 register to select the channel to transmit HDLC data
The DS26401 can only transmit HDLC data in a single DSO channel
98 H1TCS2 HDLC #1 Transmit Channel Select 2
99 H1TCS3 HDLC #1 Transmit Channel Select 3
9A H1TCS4 HDLC #1 Transmit Channel Select 4
9B H1TTSBS HDLC #1 Transmit Time Slot Bits/Sa Bits Select
9C H1RPBA HDLC #1 Receive Packet Bytes Available 0B5
RHPBA
9D H1TF HDLC #1 Transmit FIFO 1B4
THF
9E H1RF HDLC #1 Receive FIFO 0B6
RHF
9F H1TFBA HDLC #1 Transmit FIFO Buffer Available 1B3
TFBA
A0 H2TC HDLC #2 Transmit Control Unsupported function in the DS26401
A1 H2FC HDLC #2 FIFO Control Unsupported function in the DS26401
A2 H2RCS1 HDLC #2 Receive Channel Select 1 Unsupported function in the DS26401
A3 H2RCS2 HDLC #2 Receive Channel Select 2 Unsupported function in the DS26401
A4 H2RCS3 HDLC #2 Receive Channel Select 3 Unsupported function in the DS26401
A5 H2RCS4 HDLC #2 Receive Channel Select 3 Unsupported function in the DS26401
A6 H2RTSBS HDLC #2 Receive Time Slot Bits/Sa Bits Select Unsupported function in the DS26401
A7 H2TCS1 HDLC #2 Transmit Channel Select 1 Unsupported function in the DS26401
A8 H2TCS2 HDLC #2 Transmit Channel Select 2 Unsupported function in the DS26401
A9 H2TCS3 HDLC #2 Transmit Channel Select 3 Unsupported function in the DS26401
AA H2TCS4 HDLC #2 Transmit Channel Select 4 Unsupported function in the DS26401
AB H2TTSBS HDLC #2 Transmit Time Slot Bits/Sa Bits Select Unsupported function in the DS26401
AC H2RPBA HDLC #2 Receive Packet bytes Available Unsupported function in the DS26401
AD H2TF HDLC #2 Transmit FIFO Unsupported function in the DS26401
AE H2RF HDLC #2 Receive FIFO Unsupported function in the DS26401
AF H2TFBA HDLC #2 Transmit FIFO Buffer Available Unsupported function in the DS26401

BERT Functions

The DS26401 BERT functions are more full featured than the DS2155, therefore a direct register mapping is not possible. The DS26401 pseudorandom patterns are fully programmable over 32 bits compared to the fixed set of pseudorandom patterns found in the DS2155. Also, large repetitive patterns up to 512 bytes may be loaded via an indirect register. The BERT register set for the DS2155 is below but the DS26401 data sheet should be consulted for all BERT functions.

DS2155 COMMENTS
ADDRESS NAME FUNCTION
DB BAWC BERT Alternating Word Count Rate Consult DS26401 Data Sheet
DC BRP1 BERT Repetitive Pattern Set Register 1 Consult DS26401 Data Sheet
DD BRP2 BERT Repetitive Pattern Set Register 2 Consult DS26401 Data Sheet
DE BRP3 BERT Repetitive Pattern Set Register 3 Consult DS26401 Data Sheet
DF BRP4 BERT Repetitive Pattern Set Register 4 Consult DS26401 Data Sheet
E0 BC1 BERT Control Register 1 Consult DS26401 Data Sheet
E1 BC2 BERT Control Register 2 Consult DS26401 Data Sheet
E2 -- Unused Unused
E3 BBC1 BERT Bit Count Register 1 Consult DS26401 Data Sheet
E4 BBC2 BERT Bit Count Register 2 Consult DS26401 Data Sheet
E5 BBC3 BERT Bit Count Register 3 Consult DS26401 Data Sheet
E6 BBC4 BERT Bit Count Register 4 Consult DS26401 Data Sheet
E7 BEC1 BERT Error Count Register 1 Consult DS26401 Data Sheet
E8 BEC2 BERT Error Count Register 2 Consult DS26401 Data Sheet
E9 BEC3 BERT Error Count Register 3 Consult DS26401 Data Sheet
EA BIC BERT Interface Control Register Consult DS26401 Data Sheet
EB ERC Error Rate Control Register Consult DS26401 Data Sheet
EC NOE1 Number-of-Errors 1 Consult DS26401 Data Sheet
ED NOE2 Number-of-Errors 3 Consult DS26401 Data Sheet
EE NOEL1 Number-of-Errors Left 1 Consult DS26401 Data Sheet
EF NOEL2 Number-of-Errors Left 2 Consult DS26401 Data Sheet

Featured Exclusive to the DS26401

The DS26401 has many new features, which are summarized below.


Transmit-Side Synchronizer


The DS26401 has a basic synchronizer on the transmit side. This function allows the transmitter to align to the data stream present at TSER when there is no externally supplied frame sync signal available.

TSYNCC.0: Resynchronize (RESYNC). When toggled from low to high, a resynchronization of the transmit side framer is initiated. Must be cleared and set again for a subsequent resync.

TSYNCC.1: Sync Enable (SYNCE)
0 = Automatic resync enabled
1 = Automatic resync disabled

TSYNCC.2: Transmit Synchronizer Enable (TSEN)
0 = Transmit-Side Synchronizer Disabled
1 = Transmit-Side Synchronizer Enabled

TLS3.0: Loss-of-Frame Synchronization Detect (LOFD). This is a latched bit which is set when the transmit synchronizer is searching for the sync pattern in the incoming data stream.

TLS3.1: Loss of Frame (LOF). A real-time status bit which indicates that the transmit side synchronizer is searching for the synchronization pattern in the incoming data stream.

Other Functions Exclusive to the DS26401

A low-to-high transition on this bit latches the framer performance monitor counters, and the internal BERT counters (only when enabled). Each framer as well as the BERT can be independently enabled to accept this input. Must be cleared and set again to perform another counter latch.

GCR1.2: Bulk Write Enable (BWE). When this bit is set, a port write to one of the octal ports will be mapped into all eight ports. Useful for device initialization.
0 = Normal operation
1 = Bulk write is enabled

GCR1.3: Reference Clock Frequency Select (REFCLKS). This bit sets the divider ratio of the internal clock generator depending on the frequency of the reference clock input.
0 = REF_CLK is 1.544MHz
1 = REF_CLK is 2.048MHz

GCR1.4: Ganged IBO Enable (GIBO). This bit is used to select either the internal MUX for IBO operation or externally "wire-or" operation. Normally this bit should be set = 0 and the internal MUX used.
0 = Use internal IBO mux.
1 = Externally "wire-or" TSER pins and RSER pins for IBO operation.

GCR1.5: Receive Loss-of-Frame/Loss-of-Transmit Clock indication Select (RLOFLTS)
0 = RLOF/LOTCx pins indicate receive loss of frame
1 = RLOF/LOTCx pins indicate loss of transmit clock

GCR1.6: BERT Loss-of-Sync Interrupt Mask (BLOSIM)
0 = DS26401 will not generate an interrupt on INT for a BERT LOS
1 = DS26401 will generate an interrupt on INT for a BERT LOS

GCR1.7: BERT Bit Error Detect Interrupt Mask (BBEDIM)
0 = DS26401 will not generate an interrupt on INT for a BERT bit error detect
1 = DS26401 will generate an interrupt on INT for a BERT bit error detect

GCR2. 0: Receive Channel Block/Clock Select (RCBCS)
This bit controls the function of all eight RCHBLK/CLK pins.
0 = RCHBLK/CLK pins output RCHBLK(1-8) (Receive Channel Block)
1 = RCHBLK/CLK pins output RCHCLK(1-8) (Receive Channel Clock)

GCR2.1: Transmit Channel Block/Clock Select (TCBCS).
This bit controls the function of all eight TCHBLK/CLK pins.
0 = TCHBLK/CLK pins output TCHBLK(1-8) (Transmit Channel Block)
1 = TCHBLK/CLK pins output TCHCLK(1-8) (Transmit Channel Clock)

GCR2.2: Receive Frame/Multiframe Sync Select (RFMSS).
This bit controls the function of all eight RF/RMSYNC pins.
0 = RF/RMSYNC pins output RFSYNC(1-8) (Receive Frame Sync)
1 = RF/RMSYNC pins output RMSYNC(1-8) (Receive Multiframe Sync)

GCR2.3: Receive Loss-of-Signal/Signaling Freeze Select (RLOSSFS). This bit controls the function of all eight RLOS/RSIGF pins.
0 = RLOS/RSIGF pins output RLOS(1-8) (receive loss of signal)
1 = RLOS/RSIGF pins output RSIGF(1-8) (receive signaling freeze)

GCR2.6 and GCR2.7: Interleave Bus Operation Mode Select 0-1 (IBOMS0/1). These bits determine the configuration of the IBO (interleaved bus) multiplexer. These bits should be with the Rx and Tx IBO control registers within each of the framer units. Additional information concerning the IBO mux is given in the data sheet.

IBOMS1 IBOMS0 IBO Mode
0 0 IBO Mux Disabled
0 1 4.096MHz (2 per)
1 0 8.192MHz (4 per)
1 1 16.384MHz (8 per)

RCR.1: Receive RAI Integration Enable (RAIIE). In T1 ESF mode, the RAI indication can be interrupted for a period not to exceed 100ms per interruption as stated in ANSI T1.403. In T1 ESF mode, setting RAIIE will cause the RAI status from the DS26401 to be integrated for 200ms.
0 = RAI detects when 16 consecutive patterns of 00FF appear in the FDL. RAI clears when 14 or less patterns of 00FF hex out of 16 possible appear in the FDL
1 = RAI detects when the condition has been present for greater than 200ms. RAI clears when the condition has been absent for greater than 200ms.

RCR3.7: Input Data Format (IDF)
0 = Bipolar data is expected at RPOS and RNEG (either AMI or B8ZS)
1 = NRZ data is expected at RPOS. The BPV counter will be disabled and RNEG will be ignored by the DS26401.

RRTS1.0: Receive Loss-of-Frame Condition (RLOF). Set when the DS26401 is not synchronized to the received data stream.

RRTS1.1: Receive Loss-of-Signal Condition (RLOS). Set when 255 (or 2048 if RCR2.0 = 1) consecutive zeros have been detected at RPOS and RNEG.

RRTS1.2: Receive Alarm Indication Signal Condition (RAIS). Set when an unframed all one's code is received at RPOS and RNEG.

RRTS1.3: Receive Remote Alarm Indication Condition (RRAI). Set when a remote alarm is received at RPOS and RNEG.

RRTS3.0:(T1 MODE) Loop-Up Code Detected Condition (LUP). Set when the loop-up code as defined in the RUPCD1/2 register is being received.

RRTS3.0:(E1 MODE) Receive Distant MF Alarm Condition (RDMA). Set when bit-6 of time slot 16 in frame 0 has been set for two consecutive multiframes. This alarm is not disabled in the CCS signaling mode.

RRTS3.1:(T1 MODE) Loop-Down Code Detected Condition (LDN). Set when the loop-down code as defined in the RDNCD1/2 register is being received.

RRTS3.1: (E1 MODE) V5.2 Link Detected Condition (V52LNK). Set on detection of a V5.2 link identification signal (G.965).

RRTS3.2: Spare Code Detected Condition (LSP). Set when the spare code as defined in the RSCD1/2 registers is being received.

RRTS3.3: Loss-of-Receive Clock Condition (LORC). Set when the RCLK pin has not transitioned for one channel time.

RLS4.2: One-Second Timer (1SEC). Set every one-second interval based on RCLK.

RLS7.3: Receive SLC-96 Alignment Event (RSLC96). Set when a valid SLC-96 alignment pattern is detected in the Fs bit stream, and the RSLCx registers have data available for retrieval. (Section 11.12)

RLS7.5: Receive RAI-CI Detect (RRAI-CI). Set when an RAI-CI pattern has been detected by the receiver (see Section 11.5.1). This bit is active in ESF framing mode only, and will set only if an RAI condition is being detected (RRTS1.3). When the host reads (and clears) this bit, it will set again each time the RAI-CI pattern is detected (approximately every 1.1 seconds).

ERCNT.6: Manual Counter Update Select (MCUS). When manual update mode is enabled with EAMS, this bit can be used to allow the GLCE bit in GCR1 to latch all counters. Useful for synchronously latching counters of multiple framers.
0 = MECU is used to manually latch counters.
1 = GLCE is used to manually latch counters.

ERCNT.7: One-Second Select (1SECS). When timed update is enabled by EAMS, setting this bit for a specific framer will allow that framer's counters to latch on the 1 second reference from framer #1. Note that this bit should always be clear for framer #1.
0 = Use internally generated 1 second timer.
1 = Use 1 second timer from framer #1.

RESCR.4: Receive Slip Zone Select (RSZS). This bit determines the minimum distance allowed between the elastic store read and write pointers before forcing a controlled slip. This bit is only applies during T1 to E1 or E1 to T1 conversion applications.
0 = force a slip at 9 bytes or less of separation (used for clustered blank channels)
1 = force a slip at 2 bytes or less of separation (used for distributed blank channels)

RBOCC.4 to RBOCC.5: Receive BOC Disintegration bits (RBD0, RBD1). The BOC Disintegration filter sets the number of message bits that must be received without a valid BOC in order to set the BC bit indicating that a valid BOC is no longer being received.

RBD1 RBD0 CONSECUTIVE MESSAGE BITS FOR
BOC CLEAR IDENTIFICATION
0 0 16
0 1 32
1 0 48
1 1 64

TCR3.1: Insert BPV (IBPV). A 0-to-1 transition on this bit will cause a single bipolar violation (BPV) to be inserted into the transmit data stream. Once this bit has been toggled from a 0 to a 1, the device waits for the next occurrence of three consecutive ones to insert the BPV. This bit must be cleared and set again for a subsequent error to be inserted.

TIOCR.3: TSSYNC Mode Select (TSSM). Selects frame or multiframe mode for the TSSYNC pin.
0 = frame mode
1 = multiframe mode
TLS1.4: Transmit SLC96 Multiframe Event (TSLC96). When enabled by TCR2.6, this bit will set once per SLC96 multiframe (72 frames) to alert the host that new data may be written to the TSLC1-TSLC3 registers.

TESCR.4: Transmit Slip Zone Select (TSZS). This bit determines the minimum distance allowed between the elastic store read and write pointers before forcing a controlled slip. This bit only affects the elastic stores when used in T1 to E1 or E1 to T1 conversion applications.
0 = force a slip at 9 bytes or less of separation (used for clustered blank channels)
1 = force a slip at 2 bytes or less of separation (used for distributed blank channels)

For More Information

Download the DS2155 and DS26401 data sheets on our website at www.analog.com.