Section 13 8-Bit Timer (TMR)
Rev. 3.00 Jan 25, 2006 page 320 of 872
REJ09B0286-0300
13.3.1
Timer Counter (TCNT)
Each TCNT is an 8-bit readable/writable up-counter. TCNT_0 and TCNT_1 (or TCNT_Y and
TCNT_X) 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.
13.3.2
Time Constant Register A (TCORA)
TCORA is an 8-bit readable/writable register. TCORA_0 and TCORA_1 (or TCORA_Y and
TCORA_X) 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.
13.3.3
Time Constant Register B (TCORB)
TCORB is an 8-bit readable/writable register. TCORB_0 and TCORB_1 (or TCORB_Y and
TCORB_X) 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.
Summary of Contents for H8S/2158
Page 10: ...Rev 3 00 Jan 25 2006 page viii of lii...
Page 36: ...Rev 3 00 Jan 25 2006 page xxxiv of lii B Product Lineup 863 C Package Dimensions 864 Index 865...
Page 47: ...Rev 3 00 Jan 25 2006 page xlv of lii Appendix Figure C 1 Package Dimensions TBP 112A 864...
Page 54: ...Rev 3 00 Jan 25 2006 page lii of lii...
Page 70: ...Section 1 Overview Rev 3 00 Jan 25 2006 page 16 of 872 REJ09B0286 0300...
Page 118: ...Section 3 MCU Operating Modes Rev 3 00 Jan 25 2006 page 64 of 872 REJ09B0286 0300...
Page 126: ...Section 4 Exception Handling Rev 3 00 Jan 25 2006 page 72 of 872 REJ09B0286 0300...
Page 198: ...Section 6 Bus Controller Rev 3 00 Jan 25 2006 page 144 of 872 REJ09B0286 0300...
Page 326: ...Section 10 8 Bit PWM Timer PWM Rev 3 00 Jan 25 2006 page 272 of 872 REJ09B0286 0300...
Page 440: ...Section 15 Watchdog Timer WDT Rev 3 00 Jan 25 2006 page 386 of 872 REJ09B0286 0300...
Page 606: ...Section 17 I 2 C Bus Interface IIC Rev 3 00 Jan 25 2006 page 552 of 872 REJ09B0286 0300...
Page 742: ...Section 19 Multimedia Card Interface MCIF Rev 3 00 Jan 25 2006 page 688 of 872 REJ09B0286 0300...
Page 750: ...Section 21 D A Converter Rev 3 00 Jan 25 2006 page 696 of 872 REJ09B0286 0300...
Page 768: ...Section 22 A D Converter Rev 3 00 Jan 25 2006 page 714 of 872 REJ09B0286 0300...
Page 770: ...Section 23 RAM Rev 3 00 Jan 25 2006 page 716 of 872 REJ09B0286 0300...
Page 824: ...Section 26 Clock Pulse Generator Rev 3 00 Jan 25 2006 page 770 of 872 REJ09B0286 0300...
Page 844: ...Section 27 Power Down Modes Rev 3 00 Jan 25 2006 page 790 of 872 REJ09B0286 0300...
Page 878: ...Section 28 List of Registers Rev 3 00 Jan 25 2006 page 824 of 872 REJ09B0286 0300...
Page 926: ...Index Rev 3 00 Jan 25 2006 page 872 of 872 REJ09B0286 0300...