SH7020 Datasheet, PDF (292/509 Pages) Renesas Technology Corp – SuperH™ RISC engine

Buffer Mode Operation: Figure 10.48 shows an example of an operation in the buffer mode with
GRA set as an output compare register and GRA and buffer register A (BRA) set for buffer
operation. The TCNT operates as a periodic counter that is cleared by GRB compare match.
TIOCA and TIOCB are set to toggle at compare matches A and B. Since buffer mode is selected,
when TIOCA toggles at a compare match A, the BRA value is simultaneously transferred to the
GRA. This operation is repeated at every compare match A. The transfer timing is shown in figure
10.49.
TCNT value
GRB
H' 0250
H' 0200
H' 0100
H' 0000
BRA
GRA
H' 0200
H' 0250
TIOCB
TIOCA
Counter cleared by compare match B
H' 0100
H' 0200
H' 0100
H' 0200
H' 0200
Compare match A
Time
Toggle
output
Toggle
output
Figure 10.48 Buffer Mode Operation Example 1 (Output Compare Register)
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