UPD70741 Datasheet, PDF (8/112 Pages) NEC – V821TM 32-/16-BIT MICROPROCESSOR

1. PIN FUNCTIONS
1.1 Port Pins
Pin name
P00
P01
P02
P03
P04
P05
P06
P07
P08
P09
Input/output
Input/output
Function
Port 0
10-bit input/output port
Can be set for input/output bit.
Dual-function pin
TCLR
DREQ0
DACK0
DREQ1
DACK1
SI
SO
SCLK
TXD/UBE
RXD/TC
Remark After a reset is released, each port pin is set as an input port pin.
1.2 Non-Port Pins
Pin name
A0-A23
D0-D15
READY
HLDRQ
HLDAK
BLOCK
MRD
LMWR
UMWR
IORD
IOWR
UBE
RESET
X1, X2
Input/output
Function
Tristate output
Address bus signal
Tristate input/output Bidirectional data bus signal
Input
Bus cycle termination permit signal
Input
Bus mastership request signal
Output
Bus mastership permit signal
Output
Bus mastership prohibit signal
Tristate output
Read strobe signal to memory
Tristate output
Write strobe signal to lower data in memory
Tristate output
Write strobe signal to upper data in memory
Tristate output
Read strobe signal to I/O data
Tristate output
Write strobe signal to I/O data
Tristate output
Data bus upper data enable signal
Input
System reset input
Input
Crystal connection/external clock input
µPD70741
(1/2)
Dual-function pin
-
-
-
-
-
WDTOUT
-
WE
-
-
-
TXD/P08
-
-
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