2 wtbr: sub-second registers – FUJITSU MB91460 SERIES FR60 User Manual
Page 970
954
Chapter 49 Real-Time Clock
4.Registers
4.2 WTBR: Sub-Second Registers
These registers are used to hold values to be reloaded to the 21 bit down counter.
• WTBR0: Address 04A5
H
(Access: Byte, Half-word, Word)
• WTBR1: Address 04A6
H
(Access: Byte, Half-word, Word)
• WTBR2: Address 04A7
H
(Access: Byte, Half-word, Word)
Meaning of Bit Attribute Symbols (Page No.10)
The sub-second registers, WTBR, holds values to be reloaded to the 21 bit down counter. When the 21 bit
down counter value becomes “0”, the settings of WTBR are reloaded to the 21 bit down counter.
(See “
Remark: The reload value to be set in the sub-second registers corresponds to the time for half a second. One
second is reached after counting twice the reload value set in WTBR.
(See “
7.1 How do I set the count period of 1 second? (Page No.959)
WTBR0
7
6
5
4
3
2
1
0
bit
–
–
–
D20
D19
D18
D17
D16
–
–
–
X
X
X
X
X
Initial value
–
–
–
Unchanged Unchanged Unchanged Unchanged Unchanged
When reset
RX/WX
RX/WX
RX/WX
R/W
R/W
R/W
R/W
R/W
Attribute
WTBR1
7
6
5
4
3
2
1
0
bit
D15
D14
D13
D12
D11
D10
D9
D8
X
X
X
X
X
X
X
X
Initial value
Unchanged Unchanged Unchanged Unchanged Unchanged Unchanged Unchanged Unchanged
When reset
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Attribute
WTBR2
7
6
5
4
3
2
1
0
bit
D7
D6
D5
D4
D3
D2
D1
D0
X
X
X
X
X
X
X
X
Initial value
Unchanged Unchanged Unchanged Unchanged Unchanged Unchanged Unchanged Unchanged
When reset
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Attribute