Renesas SH7709S Manual Do Utilizador
Rev. 5.00, 09/03, page 337 of 760
Bits 31 to 21—Reserved: These bits are always read as 0. The write value should always be 0.
Bit 20—Direct/Indirect Selection (DI): Selects direct address mode or indirect address mode in
channel 3.
channel 3.
This bit is only valid in CHCR3. Writing to this bit is invalid in CHCR0 to CHCR2; 0 is read if
this bit is read. The write value should always be 0. When using 16-byte transfer, direct address
mode must be specified. Operation is not guaranteed if indirect address mode is specified.
this bit is read. The write value should always be 0. When using 16-byte transfer, direct address
mode must be specified. Operation is not guaranteed if indirect address mode is specified.
Bit 20: DI
Description
0
Direct address mode operation for channel 3
(Initial value)
1
Indirect address mode operation for channel 3
Bit 19—Source Address Reload Bit (RO): Selects whether the source address initial value is
reloaded in channel 2.
reloaded in channel 2.
This bit is only valid in CHCR2. Writing to this bit is invalid in CHCR0, CHCR1, and CHCR3; 0
is read if this bit is read. The write value should always be 0. When using 16-byte transfer, this bit
must be cleared to 0, specifying non-reloading. Operation is not guaranteed if reloading is
specified.
is read if this bit is read. The write value should always be 0. When using 16-byte transfer, this bit
must be cleared to 0, specifying non-reloading. Operation is not guaranteed if reloading is
specified.
Bit 19: RO
Description
0
Source address is not reloaded
(Initial value)
1
Source address is reloaded
Bit 18—Request Check Level Bit (RL): Specifies whether DRAK (
DREQ 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.
CHCR3; 0 is read if this bit is read. The write value should always be 0.
Bit 18: RL
Description
0
Active-low DRAK output
(Initial value)
1
Active-high DRAK output