DS1875 Quick Reference Guide

DS1875 Quick Reference Guide

Abstract: The DS1875 burst-mode PON controller with integrated monitoring allows programming to configure the alarms, warnings, lookup tables, and other funcTIons. The programming necessitates a large register memory map. This applicaTIon note provides a simplified view of the register map, which is convenient when programming the device.

Memory Map of the DS1875The DS1875 burst-mode PON controller features 10 separate memory tables that are internally organized into 8-byte rows.

The Lower Memory is addressed from 00h to 7Fh. It contains alarm and warning thresholds, flags, masks, several control registers, password entry area (PWE), and the Table Select byte.

Table 00h contains conversion results for MON5 through MON8.

Table 01h primarily contains user EEPROM (with PW1 level access), as well as some alarm and warning status bytes.

Table 02h is a mulTIfuncTIon space that contains configuration registers, scaling and offset values, passwords, interrupt registers, and other miscellaneous control bytes.

Table 03h is strictly user EEPROM that is protected by a PW2-level password.

Table 04h contains a temperature-indexed LUT for controlling the modulation voltage. The modulation LUT can be programmed in 2°C increments over the -40°C to +102°C range. Access to this register is protected by a PW2-level password.

Table 05h contains a temperature-indexed LUT. It allows the APC set point to change as a function of temperature to compensate for TE (tracking error). The APC LUT has 36 entries that determine the APC setting in 4°C windows between -40°C to +100°C. Access to this register is protected by a PW2-level password.

Table 06h contains a MON4-indexed LUT for controlling the M4DAC voltage. The MON4 LUT has 32 entries that are configurable to act as one 32-entry LUT of two 16-byte LUTs. When configured as one 32-byte LUT, each entry corresponds to an increment of 1/32 of the full scale. When configured as two 16-byte LUTs, the first 16 bytes and the last 16 bytes each correspond to 1/16 of full scale. Either of the two sections is selected with a separate configuration bit. Access to this register is protected by a PW2-level password.

Table 07h contains a temperature-indexed LUT for controlling the PWM reference voltage (integration of FB input). The PWM LUT has 36 entries that determine the APC setting in 4°C windows between -40°C to +100°C. Access to this register is protected by a PW2-level password.

Table 08h contains a temperature-indexed LUT for controlling the BIAS current. The BIAS LUT can be programmed in 2°C increments over the -40°C to +102°C range. Access to this register is protected by a PW2-level password.

Auxiliary memory (Device A0h) contains 256 bytes of EE memory accessible from address 00h – FFh. It is selected with the device address of A0h.

DS1875 Memory Map
More detailed image (PDF, 8kB)
Figure 1. DS1845 memory map.

Register ReferenceThe following tables provide an easy reference to the Lower Memory and Tables 00h, 01h, and 02h. For a description of the functionality for each bit, please refer to the corresponding register in the data sheet. Tables 03h through 08h are LUTs that do not require a separate reference and, therefore, not included here. Please refer to the data sheet for detailed information about these tables.

Note: RSVD is used as an acronym for Reserved.

Lower Memory Register Name Register Addr Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 TEMP ALARM HI 00h, 04h S 26 25 24 23 22 21 20 TEMP WARN HI 01h, 05h 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 TEMP ALARM LO 02h, 06h S 26 25 24 23 22 21 20 TEMP WARN LO 03h, 07h 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 VCC ALARM HI 08, 0C, 10,14, 18, 1C, 20, 24,28, 2Ch 215 214 213 212 211 210 29 28 VCC WARN HI MON1-4 ALARM HI 09, 0D, 11, 15, 19, 1D, 21, 25, 29, 2Dh 27 26 25 24 23 22 21 20 MON1-4 WARN HI VCC ALARM LO 0A, 0E, 12, 16, 1A, 1E, 22, 26, 2A, 2Eh 215 214 213 212 211 210 29 28 VCC WARN LO MON1-4 ALARM LO 0B, 0F, 13, 17, 1B, 1F, 23, 27, 2B, 2Fh 27 26 25 24 23 22 21 20 MON1-4 WARN LO PW2 EE 30h-5Fh EE EE EE EE EE EE EE EE TEMP VALUE 60h S 26 25 24 23 22 21 20 61h 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 VCC VALUE 62, 64, 66, 68, 6Ah 215 214 213 212 211 210 29 28 MON1-4 VALUE 63, 65, 67, 69, 6Bh 27 26 25 24 23 22 21 20 RESERVED 6C, 6Dh 0 0 0 0 0 0 0 0 STATUS 6Eh FETG STATUS SOFT FETG RSVD TXF RESET SOFT TXD TXF STATUS LOS STATUS RDYB UPDATE 6Fh TEMP RDY VCC RDY MON1 RDY MON2 RDY MON3 RDY MON4 RDY MON5/7 RDY MON6/8 RDY ALARM3 70h TEMP HI TEMP LO VCC HI VCC LO MON1 HI MON1 LO MON2 HI MON2 LO ALARM2 71h MON3 HI MON3 LO MON4 HI MON4 LO RSVD RSVD RSVD RSVD ALARM1 72h RSVD RSVD RSVD RSVD BIAS HI RSVD TXP HI TXP LO ALARM0 73h M3QT HI RSVD RSVD RSVD BIAS MAX RSVD RSVD RSVD WARN3 74h TEMP HI TEMP LO VCC HI VCC LO MON1 HI MON1 LO MON2 HI MON2 LO WARN2 75h MON3 HI MON3 LO MON4 HI MON4 LO RSVD RSVD RSVD RSVD RESERVED 76h, 77h RSVD RSVD RSVD RSVD RSVD RSVD RSVD RSVD DOUT 78h M3QT RESET SOFT M3QT RSVD RSVD D3 OUT D2 OUT D1 OUT D0 OUT DIN 79h INV M3QT MUX M3QT INV LOS MUX LOS D3 IN D2 IN D1 IN D0 IN RESERVED 7Ah RSVD RSVD RSVD RSVD RSVD RSVD RSVD RSVD PASSWORD ENTRY 7Bh 231 230 229 228 227 226 225 224 7Ch 223 222 221 220 219 218 217 216 7Dh 215 214 213 212 211 210 29 28 7Eh 27 26 25 24 23 22 21 20 TABLE SELECT 7Fh 27 26 25 24 23 22 21 20
Table 00h Register Name Address Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 MON5–MOND8 VALUE 80, 82, 84, 86h 215 214 213 212 211 210 29 28 81, 83, 85, 87h 27 26 25 24 23 22 21 20
Table 01h Register Name Address Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 PW1 EEPROM 80h–F7h EE EE EE EE EE EE EE EE ALARM3 F8h TEMP HI TEMP LO VCC HI VCC LO MON1 HI MON1 LO MON2 HI MON2 LO ALARM2 F9h MON3 HI MON3 LO MON4 HI MON4 LO RSVD RSVD RSVD RSVD ALARM1 FAH RSVD RSVD RSVD RSVD BIAS HI RSVD TXP HI TXP LO ALARM0 FBH M3QT HI RSVD RSVD RSVD BIAS MAX RSVD RSVD RSVD WARN3 FCh TEMP HI TEMP LO VCC HI VCC LO MON1 HI MON1 LO MON2 HI MON2 LO WARN2 FDh MON3 HI MON3 LO MON4 HI MON4 LO RSVD RSVD RSVD RSVD RESERVED FEh–FFh RSVD RSVD RSVD RSVD RSVD RSVD RSVD RSVD
Table 02h Register Name Address Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 MODE 80H SEEB RSVD PWM EN M4DAC EN AEN MOD EN APC EN BIAS EN T INDEX 81h 27 26 25 24 23 22 21 20 MOD DAC 82h 27 26 25 24 23 22 21 20 APC DAC 83h 27 26 25 24 23 22 21 20 V INDEX 84h 27 26 25 24 23 22 21 20 M4DAC 85h 27 26 25 24 23 22 21 20 DEVICE ID 86H 0 1 1 1 0 1 0 1 DEVICE VER 87H DEVICE VERSION UPDATE RATE 88h EE EE PWM_FR1 PWM_FR0 APC_SR3 APC_SR2 APC_SR1 APC_SR0 CONFIG 89h FETG DIR TXF LEN M3QT LEN ASEL BOLFS RSSI_FC RSSI_FF EN5TO8B RESERVED 8Ah RSVD RSVD RSVD RSVD RSVD RSVD RSVD RSVD MOD RANGING 8Bh RSVD RSVD RSVD RSVD RSVD MOD2 MOD1 MOD0 DEVICE ADDRESS 8Ch 27 26 25 24 23 22 21 20 COMP RANGING 8Dh RSVD BIAS2 BIAS1 BIAS0 RSVD APC2 APC1 APC0 RIGHT SHIFT1 8Eh RSVD MON12 MON11 MON10 RSVD MON22 MON21 MON20 RIGHT SHIFT0 8Fh RSVD MON32 MON31 MON30 RSVD MON42 MON41 MON40 RESERVED 90h–91h RSVD RSVD RSVD RSVD RSVD RSVD RSVD RSVD VCC SCALE MON1-2 SCALE
MON3 FINE SCALE
MON4 SCALE
MON3 COARSE SCALE 92, 94, 96, 98, 9A, 9Ch 215 214 213 212 211 210 29 28 93, 95, 97, 99, 9B, 9Dh 27 26 25 24 23 22 21 20 RESERVED 9Eh–A1h RSVD RSVD RSVD RSVD RSVD RSVD RSVD RSVD VCC OFFSET MON1-2 OFFSET MON3 FINE OFFSET MON4 OFFSET MON3 COARSE OFFSET A2, A4, A6, A8, AA, ACh S S 215 214 213 212 211 210 A3, A5, A7, A9, AB, ADh 29 28 27 26 25 24 23 22 INTERNAL TEMP OFFSET AEh S 28 27 26 25 24 23 22 AFh 21 20 2-1 2-2 2-3 2-4 2-5 2-6 PW1 B0h 231 230 229 228 227 226 225 224 B1h 223 222 221 220 219 218 217 216 B2h 215 214 213 212 211 210 29 28 B3h 27 26 25 24 23 22 21 20 PW2 B4h 231 230 229 228 227 226 225 224 B5h 223 222 221 <220/td> 219 218 217 216 B6h 215 214 213 212 211 210 29 28 B7h 27 26 25 24 23 22 21 20 FETG ENABLE1 B8h TEMP EN VCC EN MON1 EN MON2 EN MON3 EN MON4 EN RSVD RSVD FETG ENABLE0 B9H TXP HI EN TXP LO EN BIAS HI EN BIAS MAX EN RSVD RSVD RSVD RSVD TX-F ENABLE1 BAH TEMP EN VCC EN MON1 EN MON2 EN MON3 EN MON4 EN RSVD RSVD TX-F ENABLE0 BBH TXP HI EN TXP LO EN BIAS HI EN BIAS MAX EN RSVD RSVD RSVD FETG EN HTXP BCh 27 26 25 24 23 22 21 20 LTXP BDh 27 26 25 24 23 22 21 20 HBIAS BEh 27 26 25 24 23 22 21 20 MAX IBIAS BFh 212 211 210 29 28 27 26 25 DPU C0h INV M3QT MUX M3QT INV LOS MUX LOS D3 CNTL D2 CNTL D1 CNTL D0 CNTL RESERVED C1h–C2h RSVD RSVD RSVD RSVD RSVD RSVD RSVD RSVD M3QT DAC C3h 27 26 25 24 23 22 21 20 DAC1 C4h 27 26 25 24 23 22 21 20 RESERVED C5h–C6h RSVD RSVD RSVD RSVD RSVD RSVD RSVD RSVD M4 LUT CNTL C7h RSVD RSVD RSVD RSVD FBOL FBCL DBL_SB UP_LOWB MON5-8 SCALE C8, CA, CC, CEh 215 214 213 212 211 210 29 28 C9, CB, CD, CFh 27 26 25 24 23 22 21 20 MON5-8 OFFSET D0, D2, D4, D6h S S 215 214 213 212 211 210 D1, D3, D5, D7h 29 28 27 26 25 24 23 22 EMPTY D8h–F7h EMPTY MAN IBIAS F8h RSVD RSVD 212 211 210 29 28 27 F9h 27 26 25 24 23 22 21 20 MAN_CNTL FAh RSVD RSVD RSVD RSVD RSVD RSVD RSVD MAN_CLK BIAS DAC FBh BOL 0 212 211 210 29 28 27 FCh 27 26 25 24 23 22 21 20 BIAL OL FDh 27 26 25 24 23 22 21 20 PWM DAC FEh 27 26 25 24 23 22 21 20 RESERVED FFh RSVD RSVD RSVD RSVD RSVD RSVD RSVD RSVD