WE229C Integrated Circuit Analysis

[segaloco]

Just sharing this analysis in case it helps someone else.  I've been puzzling on what the WE229C is for a while, I got one with a random assortment of chips that also included a WE212C MAC-8 CPU.

After doing some digging around in schematics, I think I've got the basic pinout and some characteristics figured out:

1 ZZ_A - NC
2 MRESET - NC
3 CLMP_x - Received line signal detector clamp
4 CF_OX - Received line signal detector
5 BB_X - Received data
6 BA_X - Transmitted data
7 NFSQ_X - NF squelch
8 DLB_X - Digital loop-back mode
9 RCR_X - Receipt control register
10 TEST_X - Test mode
11 LIMIN_X - Limited signal (1585,1765-2345)Hz
12 DEMRST - NC
13 FCD_X - Fast carrier demodulator
14 AMPDET_X - Oscillator test point
15 CR_X - Carrier detector reset
16 ZC_OUT - NC
17 TSPAD - NC
18 ZZ_B - NC
19 HISPD - Connects to crosspoint 3 on switch module 3 (KS-21193)
20 ZZ_C - NC
21 NC - NC
*22 TNSLNB
*23 E291B
*24 E191B
*25 C611NB
*26 B1112
*27 PH₃
*28 PH₂
*29 PH₄
*30 H4G
*31 PH₁
^32 V_DD
^33 V_GG
^34 V_SS
^35 RESET
^36 CD_X
^37 LMP_X
*38 TDI
*39 MODINB
*40 CFM

This is from (SD-1D243-01): https://telecomarchive.s3.us-east-2.amazonaws.com/docs/bsp-archive/SD/SD-1D243-01_I6B1.pdf

V_SS is +5V and V_DD is GND so I'm assuming this is implemented in PMOS. Pins marked * connect directly to another IC given as KS-21217 (KS-* codes indicate a part from an external vendor). Pins marked ^ are shared between these two ICs and their respective buses. Some notes are given on the remaining pins.  The pins suggest an ASIC with perhaps a 4-bit UART or related element inside.

Further information can be gleaned in the circuit description for this schematic: https://telecomarchive.s3.us-east-2.amazonaws.com/docs/bsp-archive/CD/CD-1D243-01_I3B1_C.pdf

This is the best I've been able to find short of a datasheet.  I really wish I could turn up even just a listing of all WE2xx chip codes, because 200-series appear to be their complex computation elements.  The circuit manuals I have only list members of the 41-series (digital logic) and 502-series (linear) as well as some odds and ends.  This literature also is from 1976 at the latest.  WECos LSI explodes after this year, so the 1976 literature is pretty stark compared with how much silicon WECo was actually shipping towards the end of the 70s into divestiture.