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6 timer counter (tcnt), 7 timer general register (tgr) – Renesas SH7641 User Manual

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Section 18 Multi-Function Timer Pulse Unit (MTU)

Rev. 4.00 Sep. 14, 2005 Page 553 of 982

REJ09B0023-0400

Bit Bit

Name

Initial
value R/W

Description

0

TGFA

0

R/(W) Input Capture/Output Compare Flag A

Status flag that indicates the occurrence of TGRA input
capture or compare match. Only 0 can be written, for
flag clearing.

[Setting conditions]

• When TCNT = TGRA and TGRA is functioning as

output compare register

• When TCNT value is transferred to TGRA by input

capture signal and TGRA is functioning as input

capture register

[Clearing condition]

• When 0 is written to TGFA after reading TGFA = 1
For DMA, 0 must not be written to after reading
TGFA = 1. This flag is cleared only by hardware.*

Note: Write 0 after reading TGFA=1 only when a DMA address error occurs during a DMA read

cycle.

18.3.6

Timer Counter (TCNT)

The TCNT registers are 16-bit readable/writable counters. The MTU has five TCNT counters, one
for each channel.

The TCNT counters are initialized to H'0000 by a power-on reset and in standby mode.

The TCNT counters cannot be accessed in 8-bit units; they must always be accessed as a 16-bit
unit.

18.3.7

Timer General Register (TGR)

The TGR registers are dual function 16-bit readable/writable registers, functioning as either output
compare or input capture registers. The MTU has 16 TGR registers, four each for channels 0, 3,
and 4 and two each for channels 1 and 2. TGRC and TGRD for channels 0, 3, and 4 can also be
designated for operation as buffer registers. The TGR registers cannot be accessed in 8-bit units;
they must always be accessed in 16-bit units. TGR buffer register combinations are TGRA to
TGRC and TGRB to TGRD.

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