R8C2K datasheet(453/471 Pages) RENESAS

453 / 471 page

R8C/2K Group, R8C/2L Group

23. Usage Notes

Rev.1.10

Dec 21, 2007

Page 436 of 450

REJ09B0406-0110

• The TRD1 register counts 1, 0, FFFFh, 0, 1, in that order, when changing from decrement to increment

operation.

The UDF bit is set to 1 when changing between 1, 0, and FFFFh operation. Also, when bits CMD1 to CMD0

in the TRDFCR register are set to 10b (complementary PWM mode, buffer data transferred at underflow in

the TRD1 register), the content in the buffer registers (TRDGRD0, TRDGRC1, and TRDGRD1) is transferred

to the general registers (TRDGRB0, TRDGRA1, and TRDGRB1). During FFFFh, 0, 1 operation, data are not

transferred to registers such as the TRDGRB0 register. Also, at this time, the OVF bit remains unchanged.

Figure 23.5

Operation when TRD1 Register Underflows in Complementary PWM Mode

No change

UDF bit in

TRDSR0 register

Transferred from

buffer register

TRDGRB0 register

TRDGRA1 register

TRDGRB1 register

Count value in TRD0

Set to 0 by a program

Not transferred from buffer register

When bits CMD1 to CMD0 in the

TRDFCR register are set to 10b

(transfer from the buffer register to the

general register when the TRD1 register

underflows).

OVF bit in

TRDSR0 register

FFFFh

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