Fujitsu FR81S User Manual
CHAPTER 27: UP/DOWN COUNTER
6. Operation and Setting Procedure Examples
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : UP/DOWN COUNTER
FUJITSU SEMICONDUCTOR CONFIDENTIAL
FUJITSU SEMICONDUCTOR CONFIDENTIAL
22
· Reload compare function
This function is a combination of the reload and compare functions. The counter decrements and
increments between "0000
increments between "0000
H
" and a value set in the reload compare register (RCR), enabling counting in
any range. See "
■ Counting" in "6.2. Operation in Up/down Count Mode".
This function is not available in timer mode.
Table 6-1 shows the setting method for the reload/compare functions.
Table 6-1 Setting Method for Reload/Compare Functions
RLDE
UCRE
Description
0
0
Disables the reload and compare functions.
0
1
Disables the reload function.
Enables the compare function
1
0
Enables the reload function.
Disables the compare function.
1
1
Enables the reload and compare functions.
Functions of ZIN pin
One of the following functions can be selected as the function of the ZIN pin using the CGSC bit of the
counter control register (CCR).
counter control register (CCR).
· Counter clear function (CGSC=0)
If an effective edge is input from the ZIN pin during counting, the counter value is cleared to "0000
H
".
· Gate function (CGSC=1)
Operates the counter only when an effective level of signal is being entered from the ZIN pin.
Using the CGE1 and CGE0 bits of the counter control register (CCR), select either the effective edge if the
counter clear function is selected or the effective level if the gate function is selected.
counter clear function is selected or the effective level if the gate function is selected.
CGE1
CGE0
If the counter clear function is
selected (CGSC=0)
If the gate function is selected
(CGSC=1)
0
0
Disables signal edge detection.
Disables signal level detection
(disabled counting)
(disabled counting)
0
1
Falling edge
"L" level
1
0
Rising edge
"H" level
1
1
Disables setting
Disables setting
MB91520 Series
MN705-00010-1v0-E
1029