--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tcsm2-notes/tr16	Wed May 29 02:26:13 2024 +0000
@@ -0,0 +1,32 @@
+TR16-S is the 16-channel transcoder card, providing 16 TRAU channels.
+Examination of the board reveals the following major components:
+
+Global for the whole TR16-S:
+
+One Lattice ispLSI1032E: a programmable logic device, non-volatile configuration
+bits inside.
+
+One CY62128BLL-70SI chip: 128K x 8 static RAM.
+
+Replicated 16x, one set for each TRAU channel:
+
+One DSP chip, has these markings in addition to TI logo:
+
+	TRLPRB 1.1
+	D36884PZ-66
+	ADW-4BAORLW
+
+I had no success in finding any documentation for this DSP chip - was it one of
+those semi-custom Skunkworks parts without public documentation?  I surmise
+(without any proof!) that it is probably based on C54x architecture.
+
+In addition to this DSP, there is one more chip replicated 16x per channel, one
+next to each DSP: IDT 71V016, 64K x 16 static RAM.
+
+Note the absence of any flash or other non-volatile memory chips: there is
+non-volatile storage of configuration bits inside the Lattic PLD, but that's
+just logic, no code.  The available documentation for TCSM2 strongly suggests
+that operational DSP code is loaded from TRCO, presumably on each system boot,
+but what about boot code, how does the "cold" TR16-S card communicate with TRCO?
+The custom DSP ASICs probably have some ROM in them, supporting boot and maybe
+providing some common routines or tables for the operational code, who knows...

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tcsm2-notes/trco	Wed May 29 02:26:13 2024 +0000
@@ -0,0 +1,30 @@
+Major components on TRCO board:
+
+1x Lattice ispLSI1032E PLD, same as on TR16-S
+1x CPU: Intel TN80C186EB20
+
+1x really big oscillator component, labeled 16.384 MHz, likely OCXO
+1x MAS9316N DAC close to it - likely TDM common clock for the system
+
+3x Infineon chips, 2x SAB 82525 (2x HDLC) and 1x SAB 82526 (1x HDLC):
+the 5 HDLC channels which the available documentation touches on
+
+8x PLCC32 chips (9 pins on wide side, 7 pins on narrow side) with stickers
+on them that obscure the markings underneath.  The markings read IC45 through
+IC48 in the top row of 4, IC55 through IC58 in the bottom row of 4.  All 8
+ICs are directly soldered.  Suspected flash memory.
+
+Next to these 8 ICs there is a socketed PLCC44 IC (11 pins on each side)
+with a sticker that reads:
+
+	TRCO
+	6.1-0
+	TC1ROMQL
+
+It is clearly a programmed part of some kind, but not clear if it is flash
+(boot code?) or some PLD or whatever.
+
+Further insight can be gained by peeling off the stickers, but I am not going
+there yet: my current plan is to try powering this unit as-is and see if it
+comes to life in a useful way.  If it turns out to lack the needed fw, or lack
+TFO feature, then proceed further with reverse eng.