Bit 7—Data Transfer Enable (DTE): Together with the DTME bit in DTCRB, this bit enables or
disables data transfer on the channel. When the DTME and DTE bits are both set to 1, the channel
is enabled. If auto-request is specified, data transfer begins immediately. Otherwise, the channel
waits for transfers to be requested. When the specified number of transfers have been completed,
the DTE bit is automatically cleared to 0. When DTE is 0, the channel is disabled and does not
accept transfer requests. DTE is set to 1 by reading the register when DTE is 0, then writing 1.
Bit 7
DTE
Description
0
Data transfer is disabled (DTE is cleared to 0 when the specified number (Initial value)
of transfers have been completed)
1
Data transfer is enabled
If DTIE is set to 1, a CPU interrupt is requested when DTE is cleared to 0.
Bit 6—Data Transfer Size (DTSZ): Selects the data size of each transfer.
Bit 6
DTSZ
Description
0
Byte-size transfer
(Initial value)
1
Word-size transfer
Bit 5—Source Address Increment/Decrement (SAID) and Bit 4—Source Address
Increment/Decrement Enable (SAIDE): These bits select whether the source address register
(MARA) is incremented, decremented, or held fixed during the data transfer.
Bit 5
Bit 4
SAID
SAIDE
Description
0
0
MARA is held fixed
(Initial value)
1
MARA is incremented after each data transfer
• If DTSZ = 0, MARA is incremented by 1 after each transfer
• If DTSZ = 1, MARA is incremented by 2 after each transfer
1
0
MARA is held fixed
1
MARA is decremented after each data transfer
• If DTSZ = 0, MARA is decremented by 1 after each transfer
• If DTSZ = 1, MARA is decremented by 2 after each transfer
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