NEC PD754144 User Manual page 144

(4) Application of 8-bit timer counter mode
As an interval timer that generates an interrupt at 50 ms intervals
• Set the higher 4 bits of the timer counter mode register (TMn) to 0100B, and select 62.5 ms (at f
4.19 MHz of µ PD754244) as the longest set time.
• Set the lower 4 bits of TMn to 1100B.
• The set value of the timer counter modulo register (TMODn) is as follows:
50 ms
= 205
244 µ s
<Program example>
SEL MB15
MOV XA, #0CCH
MOV TMODn, XA
MOV XA, #01001100B
MOV TMn, XA
EI
EI IETn
Note This example applies to the operation of the µ PD754244 at f
of the µ PD754244 and f
time are different even if the settings are the same.
Remark n = 0 to 2
144
CHAPTER 6 PERIPHERAL HARDWARE FUNCTION
CDH
; or CLR1 MBE
; Sets modulo
; Sets mode and starts timer
; Enables interrupt
; Enables timer interrupt
= 1.0 MHz operation of the µ PD754144, the longest set time and the interval
CC
User's Manual U10676EJ3V0UM
Note
= 4.19 MHz. With f = 6.0 MHz operation
X X
=
X