MOTOROLA
MC68341 USER'S MANUAL
6- 29
CONF—Configuration Error
A configuration error results when either the SAR or the DAR contains an address that
does not match the port size specified in the CCR and the BTC register does not match
the larger port size or is zero.
1 = The CCR STR bit is set, and a configuration error is present.
0 = The CCR STR bit is set, and no configuration error exists. This bit is cleared by
writing a logic one or by a hardware reset. Writing a zero has no effect.
BRKP—Breakpoint
1 = The breakpoint signal was set during a DMA transfer.
0 = The breakpoint signal was not set during a DMA transfer. This bit is cleared by
writing a logic one or by a hardware reset. Writing a zero has no effect.
Bits 1, 0—Reserved by Motorola
NOTE
The CSR is cleared by writing $7C to its location. The DMA
channel cannot be started until the CSR DONE, BES, BED,
CONF and BRKP bits are cleared.
6.7.4 Destination Address Register (DAR)
The DAR is a 32-bit register that contains the address of the destination operand used by
the DMA to write to memory or peripheral registers. This register is accessible in either
supervisor or user space. The DAR can always be read or written to when the DMA module
is enabled (i.e., the STP bit in the MCR is cleared).
DAR1, DAR2
$790, $7B0
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
A31
A30
A29
A28
A27
A26
A25
A24
A23
A22
A21
A20
A19
A18
A17
A16
RESET:
UUUUUUUUUUUUUUUU
15
14
13
12
11
10
9876543210
A15
A14
A13
A12
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
RESET:
UUUUUUUUUUUUUUUU
U = Unaffected by reset
Supervisor/User
During the DMA write cycle, this register drives the address on the address bus. This
register can be programmed to increment (CCR DAPI bit set) or remain constant (CCR
DAPI bit cleared) after each operand transfer.
The register is incremented using unsigned arithmetic and will roll over if overflow occurs.
For example, if a register contains $FFFFFFFF and is incremented by 1, it will roll over to
$00000000. This register can be incremented by 1, 2, or 4, depending on the size of the
operand and the starting address. If the operand size is byte, the register is always
incremented by 1. If the operand size is word and the starting address is word aligned, the
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
..
.