Motorola ColdFire MCF5281 - Manual (Page 306)

DMA Controller Module
16-10 Freescale Semiconductor
16.4.5 DMA Status Registers (DSR0–DSR3)
In response to an event, the DMA controller writes to the appropriate DSRn bit, Figure 16-9 . Only a write
to DSRn[DONE] results in action.
Table 16-4 describes DSRn fields.
15 AT AT is available only if MPARK[BCR24BIT] = 1.
DMA acknowledge type. Controls whether acknowledge information is provided for the entire transfer
or only the final transfer.
0 Entire transfer. DMA acknowledge information is displayed anytime the channel is selected as the
result of an external request.
1 Final transfer (when BCR reaches zero). For dual-address transfer, the acknowledge information
is displayed for both the read and write cycles.
14–0 — Reserved, should be cleared.
7 6 5 4 3 2 1 0
Field — CE BES BED — REQ BSY DONE
Reset 0000_0000
R/W R/W
Address IPSBAR + 0x110, 0x150, 0x190, 0x1D0
Figure 16-9. DMA Status Registers (DSRn)
Table 16-4. DSRn Field Descriptions
Bits Name Description
7 — Reserved, should be cleared.
6 CE Configuration error. Occurs when BCR, SAR, or DAR does not match the requested transfer size,
or if BCR = 0 when the DMA receives a start condition. CE is cleared at hardware reset or by writing
a 1 to DSR[DONE].
0 No configuration error exists.
1 A configuration error has occurred.
5 BES Bus error on source
0 No bus error occurred.
1 The DMA channel terminated with a bus error during the read portion of a transfer.
4 BED Bus error on destination
0 No bus error occurred.
1 The DMA channel terminated with a bus error during the write portion of a transfer.
3 — Reserved, should be cleared.
2 REQ Request
0 No request is pending or the channel is currently active. Cleared when the channel is selected.
1 The DMA channel has a transfer remaining and the channel is not selected.
Table 16-3. DCRn Field Descriptions (continued)
Bits Name Description
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3