Fujitsu FR81S User Manual
CHAPTER 27: UP/DOWN COUNTER
4. Registers
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : UP/DOWN COUNTER
FUJITSU SEMICONDUCTOR CONFIDENTIAL
FUJITSU SEMICONDUCTOR CONFIDENTIAL
9
4.1. Reload Compare Register (RCR0, RCR1)
The bit configuration of the reload compare register is shown below.
This register sets reload and compare values of the up/down counter.
The reload value is the one from which counting starts at counting down; the compare value is compared
with the value counted at counting up (in other words, this value indicates that counting continues until this
value is reached). The reload and compare values are the same.
with the value counted at counting up (in other words, this value indicates that counting continues until this
value is reached). The reload and compare values are the same.
RCRH0 : Address 0F70
H
(Access : Half-word, Word)
RCRH1 : Address 0F80
H
(Access : Half-word, Word)
bit15
bit14
bit13
bit12
bit11
bit10
bit9
bit8
D15
D14
D13
D12
D11
D10
D9
D8
Initial value
X
X
X
X
X
X
X
X
Attribute
RX,W
RX,W
RX,W
RX,W
RX,W
RX,W
RX,W
RX,W
RCRL0 : Address 0F71
H
(Access : Byte, Half-word, Word)
RCRL1 : Address 0F81
H
(Access : Byte, Half-word, Word)
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
D7
D6
D5
D4
D3
D2
D1
D0
Initial value
X
X
X
X
X
X
X
X
Attribute
RX,W
RX,W
RX,W
RX,W
RX,W
RX,W
RX,W
RX,W
As shown below, this register consists of a high-order byte and a low-order byte.
· Reload compare register high-order (RCRH0, RCRH1)
· Reload compare register low-order (RCRL0, RCRL1)
· Reload compare register low-order (RCRL0, RCRL1)
In the 16-bit mode, both byte values are used. In the 8-bit mode, the low-order value is used.
When the value written in this register is transferred to the up/down count register (UDCR), the up/down
counter performs counting in the range from "0000
counter performs counting in the range from "0000
H
" ("00
H
" for 8 bits) to that value set in this register.
Notes:
· When "1" is written to the CTUT bit of the counter control register (CCR), a value set in this register can
be transferred to the up/down count register (UDCR). However, write the value in this CTUT bit of the
counter control register (CCR) while the up/down counter stops.
counter control register (CCR) while the up/down counter stops.
· If the 16-bit mode is set with the M16E bit of the counter control register (CCR) (M16E=1), this register
must always be written by half-word access.
· If the 8-bit mode is set with the M16E bit of the counter control register (CCR) (M16E=0), this register
must always be written in the reload compare register low-order side (RCRL) by byte access.
MB91520 Series
MN705-00010-1v0-E
1016