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OVERVIEW
32176 Group User’s Manual (Rev.1.01)
1.3 Pin Functions
Table 1.3.1 Description of Pin Functions (2/4)
Type
Pin Name
Signal Name
Input/Output Description
Data bus
DB0–DB15
Data bus
Input/output
This 16-bit data bus is used to connect external devices.
When writing in byte units during a write cycle, the output
data at the invalid byte position is undefined. During a
read cycle, data on the entire 16-bit bus is always read in.
However, only the data at the valid byte position is
transferred into the internal circuit.
Bus control
CS0#,CS1#
Chip select
Output
These are chip select signals for external devices.
RD#
Read
Output
This signal is output when reading an external device.
WR#
Write
Output
This signal is output when writing to an external device.
BHW#,BLW# Byte high write/
Output
When writing to an external device, this signal indicates the
Byte low write
valid byte position to which data is transferred. BHW# and
BLW# correspond to the upper address side (bits 0–7 are
valid) and the lower address side (bits 8–15 are valid),
respectively.
BHE#
Byte high enable
Output
During an external device access, this signal indicates that
the high-order data (bits 0–7) is valid.
BLE#
Byte low enable
Output
During an external device access, this signal indicates that
the low-order data (bits 8–15) is valid.
WAIT#
Wait
Input
When accessing an external device, a low-level input on
WAIT# pin extends the wait cycle.
HREQ#
Hold request
Input
This input is used by an external device to request control
of the external bus. A low-level input on HREQ# pin places
the CPU in a hold state.
HACK#
Hold acknowledge
Output
This signal notifies that the CPU has entered a hold state
and relinquished control of the external bus.
Multijunction
TIN0, TIN3,
Timer input
Input
Input pins for the multijunction timer.
timer
TIN16–TIN23
TO0–TO20
Timer output
Output
Output pins for the multijunction timer.
TCLK0
Timer clock
Input
Clock input pins for the multijunction timer.
–TCLK3
A-D converter
AVCC0
Analog power supply –
AVCC0 is the power supply for the A-D0 converter.
Connect AVCC0 to the power supply rail.
AVSS0
Analog ground
–
AVSS0 is the analog ground for the A-D0 converter.
Connect AVSS0 to ground.
AD0IN0
Analog input
Input
16-channel analog input pins for the A-D0 converter.
–AD0IN15
VREF0
Reference voltage
Input
VREF0 is the reference voltage input pin for the A-D0
input
converter.
Interrupt
SBI#
System break
Input
This is the system break interrupt (SBI) input pin for the
controller
interrupt
interrupt controller.