345
Bit 6—
DREQ
Select Bit (DS): Selects low-level or falling-edge detection as the sampling
method for the
DREQ
pin used in external request mode.
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.
In channels 0 and 1, if an on-chip peripheral module is specified as a transfer request source or an
auto-request is specified, the specification of this bit is ignored and falling-edge detection is fixed
except in an auto-request.
Bit 6: DS
Description
0
DREQ
detected by low level
(Initial value)
1
DREQ
detected at falling edge
Bit 5—Transmit Mode (TM): Specifies the bus mode when transferring data.
Bit 5: TM
Description
0
Cycle-steal mode
(Initial value)
1
Burst mode
Bits 4 and 3—Transmit Size Bits 1 and 0 (TS1, TS0): Specify the size of data to be transferred.
Bit 4: TS1
Bit 3: TS0
Description
0
0
Byte size (8 bits)
(Initial value)
0
1
Word size (16 bits)
1
0
Longword size (32 bits)
1
1
16-byte unit (4 longword transfers)
Bit 2—Interrupt Enable Bit (IE): If this bit is set to 1, an interrupt is requested on completion of
the number of data transfers specified in DMATCR (i.e. when TE = 1).
Bit 2: IE
Description
0
Interrupt request is not generated on completion of data transfers
specified in DMATCR
(Initial value)
1
Interrupt request is generated on completion of data transfers specified
in DMATCR
Summary of Contents for SH7709S
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