Electronics America Computer Hardware User Manual

202
µ PD78214 Sub-Series
Fig. 7-116 Setting of Control Registers for External Event Counter Operation
(a) Prescaler mode register 1 (PRM1)
(b) External interrupt mode register 0 (INTM0)
(c) Timer control register 1 (TMC1)
Fig. 7-117 Setting Procedure for External Event Counter Operation
7654321
0
111
0
PRM1
×
××
1
Specifies external clock input (C1)
7654321
0
0
INTM0
1 ×
×××××
Specifies valid edge of C1 input as rising edge
7654321
0
100
0
×
0
0
TMC1
×
Normal mode
Overflow flag
Enables counting
Event counter
Specify valid edge of C1 pin input
Set PRM1 register
Start counting
; Sets bit 7 of TMC1 to 1
PRM1→0F × H
CE2←1