Epson TM-U200 Series Technical Manual page 62

C o n fid e n tia l
CPU pin functions
Pin CPU
No. Function
6 AVSS
7 P60/AN0
8 P61/AN1
9 P62
10 P63
11 P64
12 P65
13 P66
14 P67
15 VCC
16 P70
17 P71
18 P72/RXD1
19 P73/CLK1
20 P74/TXD1
21 RESET
22 CLK
23 VSS
24 X1
25 X2
26 EA
27 P75
28 P76
29 P77
30 P80
31 P81/INT0
32 P82
33 ALE
34 VCC
2-20 Mechanism Configuration and Operating Principles
Signal Name I/O
AVSS I
V DTC I
HD TEMP I
NE I
DK S I
RE I
HP DTC I
DET I
AC RST I
VCC I
RTS O
CCE O
RD I
CLK IN/DTR I/O
SD O
RESET I
CLK O
VSS I
X1 I
X2 O
EA I
A16/DSW11 O
A17/DSW12 O
A18/BTDET O
WDTOUT O
CLK IN I
PF SW I
ALE O
VCC I
Level Description
(0 V) Analog/digital converter GND terminal.
Analog +24 V power voltage detection.
Analog Head temperature detection.
TTL Paper roll near-end detection.
LOW: no paper; HIGH: paper present.
TTL Drawer open/closed. LOW: open.
TTL Paper roll end detection.
LOW: paper present; HIGH: no paper.
TTL Carriage home position sensor.
LOW: home position.
TTL Host interface DET.
TTL Auto cutter position detection (reset).
(+5 V) Main power terminal.
TTL Host interface RTS. LOW: on.
TTL EP ROM/Flash ROM CE signal. LOW: active.
TTL Host interface RD. LOW: on.
TTL Host interface CLK IN/DTR.
TTL Host interface SD. LOW: on.
--- CPU reset input. LOW: on.
TTL Not used. Open.
(0 V) GND terminal.
--- Connected to ceramic vibration generator.
f=14.74 MHz ± 0.5%.
--- Connected to ceramic. f=14.74 MHz ± 0.5%.
TTL External memory access. Fixed to LOW.
TTL External memory address A16 (software)/DIP
switch 2-5 read (when P100 and P101 are LOW).
TTL External memory address A17 (software)/DIP
switch 2-6 read (when P100 and P101 are LOW).
TTL External memory address A18 (software).
TTL Watch dog timer error (and hardware limited
time power supply switch). LOW: error (reset).
TTL Connected to pin #19.
TTL Paper feed switch. LOW: active.
TTL Address latch enable signal. Latches address
on bus AD0 to AD7 at fall.
(+5 V) Main power terminal (+5 V).
Rev. A