Epson TM-U950P - B/W Dot-matrix Printer, Technical Manual

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Rev. A Mechanism Configuration and Operating Principles 2-33
TM-U950/U950P Technical Manual
ROM (512 KB, [1 M in printers with an MICR reader])
The ROM contains the printer control program and the character generator. The control
program governs the basic printer functions. The CPU operates entirely under the control of this
program.
RAM (64 KB)
The RAM is used for the following:
❏
As input buffer for data received via the connector interface.
56 A4 A4 O TTL Address signal Bit 4
57 A3 A3 O TTL Address signal Bit 3
58 A2 A2 O TTL Address signal Bit 2
59 A1 A1 O TTL Address signal Bit 1
60 A0 A0 O TTL Address signal Bit 0
61 P87 TXD O TTL TXD signal output for the interface circuit board
62 P86 RXD I TTL
RXD signal input from the interface circuit
board
63 P85 DTR O TTL DTR signal output for the interface circuit board
64 P84 CTS1 O TTL Unused (pulled down to (Vss))
65 P83 IMSD I TTL
SD signal output for the IM-403/405 serial
interface (not used on the TM-U950P)
66 P82 IMSD I TTL
RD signal input from the IM-403/405 serial
interface (not used on the TM-U950P)
67 P81 IMDTR_TM O TTL
DTR signal output for the IM-403/405 serial
interface (not used on the TM-U950P)
68 P80 CTSO O TTL Unused (pulled down to (Vss))
69 (V
cc
) - - +5V Power supply
70 (AV
cc
) - - +5V Analog power supply
71 (V
ref
) - - +5V Analog reference voltage
72 (AV
ss
) - - GND Analog power supply
73 (V
ss
) - - GND Power supply
74 P77 CACT I TTL Auto-cutter full/partial signal
75 P76 CACR I TTL Auto-cutter reset signal
76 P75 CCRP I TTL Carriage detachment sensor signal
77 P74 CHP I TTL Home position sensor signal
78 AN3 CSOE I Analog Slip paper eject sensor signal
79 AN2 CSLPIN I Analog Slip paper insert sensor signal
80 AN1 CHDTH I Analog Print head temperature sensor signal
Table 2-1. CPU Pin Assignments (continued)
Pin
number
CPU function Signal designation I/O Level Description
CONFIDENTIAL