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Chapter 41 Up/Down Counter
4.Register
4. Register
4.1 UDCC: Counter Control Register
This register is used to control behaviors of Up/Down Counter.
UDCC0 (Up/Down Counter 0): Address 0304H (Access: Byte, Half-word)
UDCC1 (Up/Down Counter 1): Address 0308H (Access: Byte, Half-word)
UDCC2 (Up/Down Counter 2): Address 0314H (Access: Byte, Half-word)
UDCC3 (Up/Down Counter 3): Address 0318H (Access: Byte, Half-word)
(For attributes, refer to “Meaning of Bit Attribute Symbols (Page No.10)”.)
bit15: Enable 16 bit mode (Up/Down Counter0 only)
* Reserved bit (Up/Down Counter 1 and 3). Be sure to write 0. The read value is the value written.
bit14: Count direction change flag (Interrupt request flag)
• When the count direction has been changed during count operation, the count direction change flag
(CDCF) is set to “1”.
• Since the count direction is set to countdown immediately after a reset, the count direction change flag
(CDCF) is set to “1” on counting up following the reset.
To enable interrupt requests, the interrupt request permission bit must be set (CFIE=“1”).
bit13: Enable count direction change interrupt request
When the interrupt request permission bit is set to “1”, the interrupt request flag (CDCF) is enabled.
bit12: Select internal prescaler
15 14 13 12 11 10 9 8 bit
M16E/
Reserved CDCF CFIE CLKS CMS1 CMS0 CES1 CES0 UDCCH
0 0 0 0 0 0 0 0 Initial value
R/W * R/W R/W R/W R/W R/W R/W R/W Attribute
76543210 bit
Reserved CTUT UCRE RLDE UDCLR CGSC CGE1 CGE0 UDCCL
0 0 0 0 1 0 0 0 Initial value
R/W0 R/W R/W R/W R1,W R/W R/W R/W Attribute
M16E Enable 16 bit mode
0 8 bit× 2 channel operation mode (8 bit mode)
1 16 bit× 1 channel operation mode (16 bit mode)
CDCF Direction change detection
When read: When written:
0 A direction change has not made. Clear the flag.
1 Direction change has been made once or more. Writing does not affect the operation.
CFIE Direction change interrupt request
0 Disable direction change interrupt requests.
1 Enable direction change interrupt requests.
CLKS Internal clock frequency
0FCLKP/2
1FCLKP/8