FreeCalypso > hg > gsm-net-reveng

comparison tcsm2-notes/trco @ 18:b36419bbc2c4

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
tcsm2-notes/trco: update after peeling off IC stickers
author Mychaela Falconia <falcon@freecalypso.org>
date Wed, 29 May 2024 23:11:28 +0000
parents 776229c5d640
children
comparison
equal deleted inserted replaced
17:776229c5d640 18:b36419bbc2c4
1 Major components on TRCO board: 1 Major components on TRCO board:
2 2
3 1x Lattice ispLSI1032E PLD, same as on TR16-S 3 1x Lattice ispLSI1032E PLD, same as on TR16-S
4 1x CPU: Intel TN80C186EB20 4 1x CPU: Intel TN80C186EB20
5 5
6 1x really big oscillator component, labeled 16.384 MHz, likely OCXO (or TCXO?) 6 Big oscillator, markings on the metal can package:
7 1x MAS9316N DAC close to it - likely TDM common clock for the system 7
8 DFA 36-TR
9 16.384 MHz
10 A36060 0049
11
12 Close to it there is a MAS9316N DAC - thus the big oscillator is likely the
13 system-wide TDM clock (the one that can be synced to various inputs), and the
14 DAC is for control loop adjustments aiming to lock this oscillator to the
15 selected external clock source. Based on the size of the can, I originally
16 thought it was an OCXO, but when I searched for "DFA 36-TR", the hits I got
17 (only sellers, no datasheet) say TCXO. Who knows...
8 18
9 3x Infineon chips, 2x SAB 82525 (2x HDLC) and 1x SAB 82526 (1x HDLC): 19 3x Infineon chips, 2x SAB 82525 (2x HDLC) and 1x SAB 82526 (1x HDLC):
10 the 5 HDLC channels which the available documentation touches on 20 the 5 HDLC channels which the available documentation touches on.
11 21
12 8x PLCC32 chips (9 pins on wide side, 7 pins on narrow side) with stickers 22 8x PLCC32 chips (9 pins on wide side, 7 pins on narrow side) with stickers
13 on them that obscure the markings underneath. The markings read IC45 through 23 on them that obscure the markings underneath. The markings read IC45 through
14 IC48 in the top row of 4, IC55 through IC58 in the bottom row of 4. All 8 24 IC48 in the top row of 4, IC55 through IC58 in the bottom row of 4. All 8
15 ICs are directly soldered. Suspected flash memory. 25 ICs are directly soldered. Suspected flash memory.
26
27 Update with IC55 sticker peeled off: the IC underneath is AM29F010B-120JC,
28 just like I suspected. Interestingly, it also says "(C) 1998 AMD" - the year
29 is slightly newer than my original assumptions of 1996 vintage.
16 30
17 Next to these 8 ICs there is a socketed PLCC44 IC (11 pins on each side) 31 Next to these 8 ICs there is a socketed PLCC44 IC (11 pins on each side)
18 with a sticker that reads: 32 with a sticker that reads:
19 33
20 TRCO 34 TRCO
22 TC1ROMQL 36 TC1ROMQL
23 37
24 It is clearly a programmed part of some kind, but not clear if it is flash 38 It is clearly a programmed part of some kind, but not clear if it is flash
25 (boot code?) or some PLD or whatever. 39 (boot code?) or some PLD or whatever.
26 40
27 Further insight can be gained by peeling off the stickers, but I am not going 41 Update after peeling off the sticker: the part is ST M27C4002, an OTP ROM!
28 there yet: my current plan is to try powering this unit as-is and see if it 42 It is clearly the boot PROM, whereas the other 8 ICs (all 29F010?) are the
29 comes to life in a useful way. If it turns out to lack the needed fw, or lack 43 flash memory array. The large size of both the flash array and the boot PROM
30 TFO feature, then proceed further with reverse eng. 44 is surprising:
45
46 * The boot PROM is 4 Mbit (256K x 16) - that's 512 KiB, half of 80186 address
47 space if fully and directly mapped.
48
49 * Assuming that the 8 bit wide 29F010 chips are wired in pairs across the
50 16 bit wide data bus, we got 1 MiB in total, in 4 banks of 256 KiB each.
51 More than 80186 can address directly - is it a bank-switched memory system?
52
53 RAM chips:
54
55 * 2x Samsung K6T1008C2E-GL70. Each of these ICs is 128K x 8 static RAM;
56 the design probably uses two of them across the 16 bit wide data bus.
57 256 KiB of RAM here.
58
59 * 1x CY62256-70SNC - 32K x 8 (256 Kbit) static RAM. What is it for???