November, 99
All Rights Reserved
15
B-443 Bar Code Printer
Service Manual
3.2 MCU Pin Description
Pin
Name
Input/Output
Function
Vcc, Vss
Power supply
Supply 5V
±
10% to Vcc and 0V to Vss.
CNVss
CNVss input
Input
This pin controls the processor mode.
Connected to Vss for single-chip mode, to
Vcc for external ROM types.
/RESET
Reset input
Input
To enter the reset state, this pin must be kept
at “ L” condition, and maintained so for the
required time.
X
IN
Clock input
Input
X
OUT
Clock output
Output
These are I/O pins of internal clock
generating circuit. Connect a ceramic or
quartz crystal resonator between X
IN
and X
OUT
.
When an external clock is used, the clock
source should be connected to the X
IN
pin,
and the X
OUT
pin should be left open.
/E
Enable output
Output
Data/instruction read and data write are
performed when output from this pin is “ L” .
BYTE
Bus width
selection input
Input
In memory expansion mode or
microprocessor mode, this pin determines
whether the external data bus is of 8-bit width
or 16-bit width. The width is 16 bits for “ L”
signal input and 8 bits for “ H” signal input.
/HOLD
/HOLD input pin
Input
This is an input pin for the /HOLD request
signal.
/RDY
/RDY input pin
Input
This is an input pin for the /RDY signal.
ϕ
1
Clock
ϕ
1 output
Output
This is the
ϕ
1 output pin, which is equal to the
clock X
IN
pin divided by 2.
ST0, ST1
Status signal
output pin
Output
The bus use status output is generated in 2-
bit code
AVcc, AVss
Analog supply
input
Power supply for the A-D converter. Connect
AV
CC
and AV
SS
to V
SS
externally.
V
REF
Reference
voltage input
Input
This is reference voltage input pin for the A-D
converter.
A0/MA0~
A7/MA7
Address low-
order/DRAM
address
Output
This is an output pin for the 8 low-order bits of
addresses. When the DRAM is to be
accessed, the row and column addresses are
generated by means of time division
multiplexing.
Summary of Contents for B-443
Page 61: ...November 99 All Rights Reserved 58 B 443 Bar Code Printer Service Manual...
Page 63: ...November 99 All Rights Reserved 60 B 443 Bar Code Printer Service Manual...
Page 65: ...November 99 All Rights Reserved 62 B 443 Bar Code Printer Service Manual 11 12...
Page 67: ...November 99 All Rights Reserved 64 B 443 Bar Code Printer Service Manual...
Page 69: ...November 99 All Rights Reserved 66 B 443 Bar Code Printer Service Manual...
