Fujitsu FR81S User Manual
CHAPTER 19: BASE TIMER
5. Operation
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER
: BASE TIMER
FUJITSU SEMICONDUCTOR CONFIDENTIAL
73
Operation that is performed if reactivation is permitted or not during counting depends on whether
reactivation is permitted based on the RTGEN bit of the timer control register (BTxTMCR).
⋅
If reactivation is not permitted (RTGEN = 0): Any activation trigger is ignored when it is entered during
counting.
⋅
If reactivation is permitted (RTGEN = 1): The TGIR bit of the base timer x status control register
(BTxSTC) changes to "1". In addition, the value of L width
setting reload register (BTxPRLL) is reloaded to the 16-bit
down counter, which starts counting.
Figure 5-18 Example of Counting Operation in Reload Mode
Counting operation when reactivation is enabled
Counting operation when reactivation is disabled
Activation trigger
Rising edge detection
Activation trigger is ignored.
PPG output waveform
Underflow
interrupt request
(UDIR bit)
Underflow
interrupt request
(UDIR bit)
Interrupt request
Trigger interrupt
request
(TGIR bit)
m : Value of base timer x L width setting reload register (BTxPRLL)
n : Value of base timer x H width setting reload register (BTxPRLH)
T : Count clock cycle
m
n
0
(1)
(1)
(2)
(2)
(2)
PPG output waveform
Rising edge detection
Reactivate with activation trigger
Activation trigger
Underflow
interrupt request
(UDIR bit)
Trigger interrupt
request
(TGIR bit)
Trigger interrupt
request
(TGIR bit)
m : Value of base timer x L width setting reload register (BTxPRLL)
n : Value of base timer x H width setting reload register (BTxPRLH)
T : Count clock cycle
m
n
0
(1)
(1)
(2)
(2)
(1)
MB91520 Series
MN705-00010-1v0-E
706