8-Bit Timer/Event Counter Cautions - NEC mPD780065 Series Preliminary User's Manual

Figure 7-12. 16-Bit Resolution Cascade Connection Mode
Count clock
TM50 00H 01H
TM51 00H
CR50
CR51
TCE50
TCE51
INTTM50
TO50
Operation permit
Count start

7.5 8-Bit Timer/Event Counter Cautions

(1) Timer start errors
An error with the maximum of one clock may occur concerning the time required for a match signal to be generated
after timer start. This is because 8-bit counter 5n (TM5n) is started asynchronously with the count pulse.
Count pulse
TM5n count
n = 0, 1
152
CHAPTER 7 8-BIT TIMER/EVENT COUNTER
N N+1 FFH 00H
01H
N
M
Interval time
Figure 7-13. 8-Bit Counter Start Timing
00H 01H
Timer start
Preliminary User's Manual U13420EJ2V0UM00
FFH 00H FFH 00H 01H
02H M–1 M
Interrupt request
generation
Level reverse
Counter clear
02H 03H
N 00H 01H A 00H
00H B 00H
Operation
stop
04H