Fujitsu FR81S Manual Do Utilizador
CHAPTER 27: UP/DOWN COUNTER
5. Interrupt
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : UP/DOWN COUNTER
FUJITSU SEMICONDUCTOR CONFIDENTIAL
FUJITSU SEMICONDUCTOR CONFIDENTIAL
19
5. Interrupt
This section shows the interrupt of the up/down counter.
An interrupt request is generated in one of the following events:
· The counting direction is inverted (Counting direction change interrupt request).
· The counter value matches the value set in the reload compare register (RCR) (Compare result match
· The counter value matches the value set in the reload compare register (RCR) (Compare result match
interrupt request).
· An overflow occurs (Overflow interrupt request).
· An underflow occurs (Underflow interrupt request).
· An underflow occurs (Underflow interrupt request).
Different interrupt requests are generated depending on the up/down counter operating mode.
Table 5-1 shows the correspondence between operating modes and interrupt requests.
Table 5-1 Correspondence between Operating Modes and Interrupt Requests
Interrupt request
Timer mode
Up/down count
mode
Phase difference count
mode (multiply-by-2/
multiply-by-4)
Counting direction change
interrupt request
interrupt request
×
○
○
Compare result match interrupt
request
request
○
○
○
Overflow interrupt request
×
○
○
Underflow interrupt request
○
○
○
Table 5-2 shows interrupts that can be used for the up/down counter.
Table 5-2 Up/Down Counter Interrupts
Interrupt request
Interrupt request
flag
Interrupt request
enable
Clearing of interrupt
request
Counting direction
change interrupt request
change interrupt request
CDCF=1 in CCR
CFIE=1 in CCR
Writing of CDCF bit to "0" in
CCR.
CCR.
Compare result match
interrupt request
interrupt request
CMPF=1 in CSR
CITE=1 in CSR
Writing of CMPF bit to "0"
in CSR.
in CSR.
Overflow interrupt
request
OVFF=1 in CSR
UDIE=1 in CSR
Writing of OVFF bit to "0" in
CSR.
CSR.
Underflow interrupt
request
UDFF=1 in CSR
UDIE=1 in CSR
Writing of UDFF bit to "0" in
CSR.
CSR.
CCR : Counter control register
CSR : Counter status register
CSR : Counter status register
MB91520 Series
MN705-00010-1v0-E
1026