342
Bit 17—Acknowledge Mode Bit (AM): Specifies whether DACK is output in the data read cycle
or in the data write cycle in dual address mode.
DACK is always output in single address mode, regardless of this bit specification.
This bit is only valid in CHCR0 and CHCR1. Writing to this bit is invalid in CHCR2 and
CHCR3; 0 is read if this bit is read. The write value should always be 0.
Bit 17: AM
Description
0
DACK output in read cycle
(Initial value)
1
DACK output in write cycle
Bit 16—Acknowledge Level (AL): Specifies whether DACK (acknowledge) signal output is
active-high or active-low.
This bit is only valid in CHCR0 and CHCR1. Writing to this bit is invalid in CHCR2 and
CHCR3; 0 is read if this bit is read. The write value should always be 0.
Bit 16: AL
Description
0
Active-low DACK output
(Initial value)
1
Active-high DACK output
Bits 15 and 14—Destination Address Mode Bits 1 and 0 (DM1, DM0): Select whether the
DMA destination address is incremented, decremented, or left fixed.
Bit 15: DM1
Bit 14: DM0
Description
0
0
Fixed destination address
(Initial value)
0
1
Destination address is incremented (+1 in 8-bit transfer, +2 in
16-bit transfer, +4 in 32-bit transfer, +16 in 16-byte transfer)
1
0
Destination address is decremented (–1 in 8-bit transfer, –2 in
16-bit transfer, –4 in 32-bit transfer; illegal setting in 16-byte
transfer)
1
1
Setting prohibited
Summary of Contents for SH7709S
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