ADSP-BF537 Blackfin Processor Hardware Reference
12-75
SPORT Controllers
DMA Initialization Sequence
Next the DMA channels for receive (channel3) and for transmit
(channel4) are set up for auto-buffered, one-dimensional, 32-bit transfers.
Again, there are other possibilities, so generic labels have been used, with a
particular value shown in the comments. See
, for a detailed explanation of the bits.
Note that the DMA channels can be enabled at the end of the configura-
tion since the SPORT is not enabled yet. However, if preferred, the user
can enable the DMA later, immediately before enabling the SPORT. The
only requirement is that the DMA channel be enabled before the associ-
ated peripheral is enabled to start the transfer.
Listing 12-2. DMA Initialization
Program_DMA_Controller:
/* Receiver (DMA channel 3) */
/* Set P0 to DMA Base Address */
P0.l = lo(DMA3_CONFIG);
P0.h = hi(DMA3_CONFIG);
/* Configuration (for instance 0x108A for Autobuffer, 32-bit
wide transfers) */
R0 = DMA_RECEIVE_CONF(z);
W[P0] = R0;
/* configuration register */
/* rx_buf = Buffer in Data memory (divide count by four because
of 32-bit DMA transfers) */
R1 = (length(rx_buf)/4)(z);
W[P0 + (DMA3_X_COUNT - DMA3_CONFIG)] = R1;
/* X_count register
*/
R1 = 4(z);
/* 4 bytes in a 32-bit transfer */
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...