4 udrc: up/down reload/compare register – FUJITSU MB91460 SERIES FR60 User Manual
Page 862
846
Chapter 41 Up/Down Counter
4.Register
4.4 UDRC: Up/Down Reload/Compare Register
This register is used to reload a value to Up/Down Counter and for comparison.
This register is also used to write to Up/Down Counter.
• UDRC10 (Up/Down Counter 0/1): Address 0300
H
(Access:
Byte, Half-Word
)
• UDRC32 (Up/Down Counter 2/3): Address 0310
H
(Access:
Byte, Half-Word
)
Depending on the setting of the 16 bit mode enable bit (CCR.M16E), this register behaves differently.
■
16 Bit Mode (M16E=“1”)
In the 16 bit mode, this register functions as 16-bit reload/compare register.
• UDCR10 (Reload compare): Address 00300
H
(Access: Byte, Half-word)
• UDCR32 (Reload compare): Address 00310
H
(Access: Byte, Half-word)
Meaning of Bit Attribute Symbols (Page No.10)
• The reload and compare values are same.
When Up/Down Counter counts up, the value in RCR is used as a compare value.
When Up/Down Counter counts down, underflow is generated and the value in RCR is used as a reload
value for reloading.
(Up/Down Counter counts between 0000
H
and the reload/compare value.)
•
In the 16 bit mode, be sure to write by
half-word access.
■
8 Bit Mode (M16E=“0”)
In the 8 bit mode, this register functions as 8-bit reload/compare register 0 and 8-bit reload/compare register 1.
• UDCR1 (reload compare 1): Address 00300
H
(Access: Byte, Half-word)
• UDCR0 (reload compare 0): Address 00301
H
(Access: Byte, Half-word)
• UDCR3 (reload compare 3): Address 00310
H
(Access: Byte, Half-word)
• UDCR2 (reload compare 2): Address 00311
H
(Access: Byte, Half-word)
Meaning of Bit Attribute Symbols (Page No.10)
• The reload and compare values are same.
When Up/Down Counter counts up, the value in RCR is used as a compare value.
When Up/Down Counter counts down, underflow is generated and the value in RCR is used as a reload
value for reloading.
(Up/Down Counter counts between 0000
H
and the reload/compare value.)
• Perform the following procedure to write to Up/Down Counter.
15
14
13
12
11
10
9
8
bit
D15
D14
D13
D12
D11
D10
D09
D08
0
0
0
0
0
0
0
0
Initial value
RX, W
RX, W
RX, W
RX, W
RX, W
RX, W
RX, W
RX, W
Attribute
7
6
5
4
3
2
1
0
bit
D07
D06
D05
D04
D03
D02
D01
D00
0
0
0
0
0
0
0
0
Initial value
RX, W
RX, W
RX, W
RX, W
RX, W
RX, W
RX, W
RX, W
Attribute
7
6
5
4
3
2
1
0
bit
D07
D06
D05
D04
D03
D02
D01
D00
0
0
0
0
0
0
0
0
Initial value
RX, W
RX, W
RX, W
RX, W
RX, W
RX, W
RX, W
RX, W
Attribute