TO EMERGENCY
EIA CHANNELS
TRANSFER UNIT
(RS-232C)
(ETU)
INTERRUPT
CIRCUITRY
/
\
—
—
BUS
ERROR
MICROPROCESSOR
CIRCUITRY
—
(68010)
LED
\
TDM
BUS
LEADS
SERIAL SERIAL SERIAL SERIAL
-48V DC
CHANNEL CHANNEL CHANNEL CHANNEL
1
2
3
4
ETU
CONTROL
EIA
CONTROL
EIA
CONTROL
RESET
CIRCUITRY
PROCESSOR
BUS
●
●
●
● ●
●
MEMORY
MANAGEMENT
NETWORK
CONTROLLER
READ
ONLY
/
SAKI
MEMORY
●
(64K)
●
●
BUFFERS
\
TIME OF
DAY
CLOCK
RANDOM
ACCESS
MEMORY
(80K)
FRONT-
PLANE
INTERFACE
—
(BUS
BUFFERS)
/
TO MEMORY
CIRCUIT
PACK VIA
FRONT PLANE
BUS
+5V DC
BATTERY
(POWER
FAIL
(DETECT)
Figure 3-2. Call Processor (ZTN82 or ZTN128) Circuitry
3-3