4-13
UP-D70/D70A (UC,CE)
4. Port Map
a) CPU (IC101) Port map
Terminal
Signal line name
I/O
Function
1
nRESET
I
Reset of CPU
2
XTAL
Clock oscillator (20MHz)
3
EXTAL
Clock oscillator (20MHz)
4
MD1
I
Appointment of CPU operation mode
5
MD0
I
Appointment of CPU operation mode
6
nNMI
I
Non maskable interrupt
7
nSTBY
I
Stand-by
8
Vss
GND
9
nARB
I
Communication between daughter boards
10
RxD
I
Receiving data
11
TxD
O
Transmission data
12
Vss
GND
13
nWAIT
I
Wait
14
ø
System clock
15
nAS
O
Address strobe
16
nWR
O
Write signal
17
nRD
O
Read signal
18
nIRQ0
I
DREQ break into
19
B2
O
Bank switch of flash memory
20
nDACK
I/O
Print data acknowledgment
21
KEY_EN0
O/Hi-Z
Key scan
22
KEY_EN1
O/Hi-Z
Key scan
23
KEY_DAT0
I
Key data
24
KEY_DAT1
I
Key data
25
KEY_DAT2
I
Key data
26
KEY_DAT3
I
Key data
27
RS
O
LCD
28
R_nW
O
LCD
29
AVss
Ground of A/D conversion
30
RBN_CD_SENS
I
Input of ribbon code sensor
31
BCD_SENS
I
Input of barcode sensor
32
OHP_SENS
I
Input of OHP sensor
33
HED_THERM
I
Thermistor value of thermal head
34
ROOM_THERM
I
Thermistor value of room
35
nCTS_LATCH
I
nCTS
36
nDREQ
I/O
Print data request
37
P77
I
38
AVcc
Power supply of A/D conversion
39
S
O
Address territory switch
40
PRNT_PLS0
O
Print pulse
