h8s-2161b Renesas Electronics Corporation., h8s-2161b Datasheet - Page 345

• Manufacturer Part Number: h8s-2161b
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

12.3.1
Each TCNT is an 8-bit readable/writable up-counter. TCNT_0 and TCNT_1 comprise a single 16-
bit register, so they can be accessed together by word access. The clock source is selected by the
CKS2 to CKS0 bits in TCR. TCNT can be cleared by an external reset input signal, compare-
match A signal or compare-match B signal. The method of clearing can be selected by the CCLR1
and CCLR0 bits in TCR. When TCNT overflows (changes from H'FF to H'00), the OVF bit in
TCSR is set to 1. TCNT is initialized to H'00.
12.3.2
TCORA is an 8-bit readable/writable register. TCORA_0 and TCORA_1 comprise a single 16-bit
register, so they can be accessed together by word access. TCORA is continually compared with
the value in TCNT. When a match is detected, the corresponding compare-match flag A (CMFA)
in TCSR is set to 1. Note however that comparison is disabled during the T2 state of a TCORA
write cycle. The timer output from the TMO pin can be freely controlled by these compare-match
A signals and the settings of output select bits OS1 and OS0 in TCSR. TCORA is initialized to
H'FF.
12.3.3
TCORB is an 8-bit readable/writable register. TCORB_0 and TCORB_1 comprise a single 16-bit
register, so they can be accessed together by word access. TCORB is continually compared with
the value in TCNT. When a match is detected, the corresponding compare-match flag B (CMFB)
in TCSR is set to 1. Note however that comparison is disabled during the T2 state of a TCORB
write cycle. The timer output from the TMO pin can be freely controlled by these compare-match
B signals and the settings of output select bits OS3 and OS2 in TCSR. TCORB is initialized to
H'FF.
12.3.4
TCR selects the TCNT clock source and the condition by which TCNT is cleared, and
enables/disables interrupt requests.
Timer Counter (TCNT)
Time Constant Register A (TCORA)
Time Constant Register B (TCORB)
Timer Control Register (TCR)
Rev. 3.00 Mar 21, 2006 page 291 of 788
Section 12 8-Bit Timer (TMR)
REJ09B0300-0300