209
The buffer registers are linked to the CPU by an internal 16-bit bus and can be written or read by
either word or byte access.
Buffer registers are initialized to H'FFFF by a reset and in standby mode.
8.2.10 Timer Control Registers (TCR)
TCR is an 8-bit register. The ITU has five TCRs, one in each channel.
Channel
Abbreviation
Function
0
TCR0
TCR controls the timer counter. The TCRs in all channels are
1
TCR1
functionally identical. When phase counting mode is selected in
2
TCR2
channel 2, the settings of bits CKEG1 and CKEG0 and TPSC2 to
3
TCR3
TPSC0 in TCR2 are ignored.
4
TCR4
Bit
Initial value
Read/Write
7
—
1
—
6
CCLR1
0
R/W
5
CCLR0
0
R/W
4
CKEG1
0
R/W
3
CKEG0
0
R/W
0
TPSC0
0
R/W
2
TPSC2
0
R/W
1
TPSC1
0
R/W
Timer prescaler 2 to 0
These bits select the
counter clock
Reserved bit
Clock edge 1/0
These bits select external clock edges
Counter clear 1/0
These bits select the counter clear source
Each TCR is an 8-bit readable/writable register that selects the timer counter clock source, selects
the edge or edges of external clock sources, and selects how the counter is cleared.
TCR is initialized to H'80 by a reset and in standby mode.