HD6417021 Hitachi Semiconductor, HD6417021 Datasheet - Page 290

• Manufacturer Part Number: HD6417021
• Description: SuperH RISC engine
• Manufacturer: Hitachi Semiconductor

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.
276 HITACHI
H' 0250
H' 0200
H' 0100
H' 0000
TIOCB
TIOCA
TCNT value
GRB
GRA
Figure 10.48 Buffer Mode Operation Example 1 (Output Compare Register)
BRA
H' 0250
H' 0200
H' 0200
H' 0100
Counter cleared by compare match B
Compare match A
H' 0100
H' 0200
H' 0200
Time
Toggle
output
Toggle
output