UPD75237 Datasheet, PDF (64/191 Pages) NEC – 4-BIT SINGLE-CHIP MICROCOMPUTER

Fig. 4-25 Timer/Event Counter Block Diagram
8 SET1^*1
8
TM0
TM07TM06 TM05 TM04 TM03TM02 — —
PORT1.3
*2
P13/TI0
Input
Buffer
From
Clock
Genera-
tor
MPX
Event Counter
#1
(Refer to Fig. 4-26)
CP
Timer Operation Start
Internal Bus
8
TMOD0
Modulo Register (8)
8
Comparator (8)
8
Match
TOUT
F/F
Reset
T0
Count Register (8)
Clear
TOE0
TO
Enable
Flag
PORT2.0
P20
Output
Latch
PGMB Bit 2
Port 2
Input
/Output
Mode
To Serial
Interface
P20/PTO0
Output
Buffer
INTT0
( ) IRQT0
Set Signal
RESET
IIRQT0
Clear
Signal
* 1. Instruction execution
2. P13/TI0 pin is an external event pulse input pin which serves as timer/event counter and event counter.