deveopmen
Intelligent I/O
Rev.B2 for proof reading
Mitsubishi Microcomputers
M32C/83 group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
245
Table 1. 23.2. Base timer specifications
Item
Specifications
Count source
f1/2(n+1)
n: Set by count source division ratio select bit
(n=0 to 31, however, please note when n=31, the counter source is not divided.)
Count operation
Up count / down count
Count start condition
Writes "1" for the start bit in the base timer start register or base timer control
register 1. (After writing the bit, the base timer resets to "0000
16
" and
counting starts.)
Count stop condition
Writes "0" for both the start bit in the base timer start register and base timer
control register 1.
(1) Synchronizes and resets the base timer with that of another group.
Group 0: Synchronizes base timer reset with the group 1 base timer.
Group 1: Synchronizes base timer reset with the group 0 base timer.
(2) Matches the value of the base timer to the value of WG register 0.
(3) Input "L" to INT pin
Group 0 : INT 0 pin
Group 1 : INT 1 pin
The above 3 factors can be used in conjunction with one another.
(1) Synchronizes and resets the base timer with that of another group.
Group 2: Synchronizes base timer reset with the group 1 base timer.
Group 3: Synchronizes base timer reset with the group 2 base timer.
(2) Matches the value of the base timer to the value of WG register 0.
(3) Reset request from communication additional circuit (group 2 only)
Count reset condition Group 0, 1
Group 2, 3
The above 3 factors can be used in conjunction with one another.
Interrupt request generation timing
When bit 14 or bit 15 overflows
Read from timer
When the base timer is running
The count is output when the base timer is read.
When the base timer not running
An undefined value is output when the base timer is read.
Write to timer
Possible. Values that are written while the base timer is resetting are
ignored. If values are written while the base timer is running, counting
continues after the values are written.
f
1
2(n+1) divider
RST0
RST1
RST2
Other base timer reset
Base timer i
b14 b15
Overflow signal
Base timer i
interrupt request
Count source
switching select bit
Interrupt timing
select bit
Reset signal
BT0S
BTS
Input "L" to INT pin
(Group 0,1)
Matched to waveform
generation register 0
Figure 1. 23.10. Base timer block diagram