Motorola MTR2000 Manual page 115

STATION CONTROL MODULE
MODEL TCN6273N
68P81094E31-I
Schematics (Sheet 16 of 36)
7/28/2007
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SERVICE NOTES DSP PROCESSING
Signal
Description/Nominal Signal Levels
Path
Abacus Current-to-Voltage and Differential to Single-ended converter. Q4400 and Q4401
A
take the current output from the Abacus chip on the receiver board and converts it to a
voltage. Then the two halves of the differential input are converted to a single output by
Q4402. Finally, Q4403 outputs a full scale 0-5V bit stream representing the Abacus
output.
Reset. Generated in the host core. Used here to reset the 56002 and U4400 (glue ASIC)
B
and to configure the IRQ lines properly for system reset
OGA. Outlaw Glue ASIC. Provides an interface to 4 PCM codecs and 1 linear codec.
C
Receives the Abacus data stream. Provides RSSI output. Divides 16.8 MHz clock to
provide both 1.2 MHz and 2.1 MHz clocks.
P4400. OnCE port for DSP emulation.
D
U4400. 56002 half or the 68356 device. Does all DSP. Has dedicated memory (U4401-
E
U4403).
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SCHEMATIC IC'S TABLE DSP PROCESSING
Reference Type
U4400 Custom IC Asic
U4401... MT5C2568 32k*8 SRAM
Description