CHAPTER 6 PERIPHERAL HARDWARE FUNCTION
159
User’s Manual U10676EJ3V0UM
(4) Application of 16-bit timer counter mode
As an interval timer that generates an interrupt at 5-second intervals
Note
•
Set the higher 4 bits of the mode register (TM1) to 0010B, and select the overflow of timer counter
count register (T2).
•
Set the higher 4 bits of TM2 to 0100B and select 16.0 second as the longest set time.
•
Set the lower 4 bits of TM1 to 0010B and select the 16-bit timer counter mode.
•
Set the lower 4 bits of TM2 to 1110B, select the 16-bit timer counter mode and count operation. Then,
issue the timer start command.
•
The set values of the timer counter modulo registers (TMOD1 and TMOD2) are as follows.
= 20491.8 – 1 500BH
<Program example>
SEL
MB15
;
or CLR1 MBE
MOV
XA, #050H
MOV
TMOD1, XA
;
Sets modulo (higher 8 bits)
MOV
XA, #00B
MOV
TMOD2, XA
;
Sets modulo (lower 8 bits)
MOV
XA, #00100010B
MOV
TM1, XA
;
Sets mode
MOV
XA, #01001110B
MOV
TM2, XA
;
Sets mode and starts timer
DI
IET1
;
Disables timer (channel 1) interrupt
EI
;
Enables interrupts
EI
IET2
;
Enables timer (channel 2) interrupt
Note
This example applies to the operation of the
µ
PD754244 at f
X
= 4.19 MHz. With f
X
= 6.0 MHz
operation of the
µ
PD754244 and f
CC
= 1.0 MHz operation of the
µ
PD754144, the longest set time
and interval time are different even if the settings are the same.
5 sec
244
µ
s