
Enhanced Direct Memory Access (eDMA)
Freescale Semiconductor
16-33
b) Write longword to location 0x2000
→
first iteration of the minor loop.
c) Read byte from location 0x1004, read byte from location 0x1005, read byte from 0x1006, read
byte from 0x1007.
d) Write longword to location 0x2004
→
second iteration of the minor loop.
e) Read byte from location 0x1008, read byte from location 0x1009, read byte from 0x100A, read
byte from 0x100B.
f) Write longword to location 0x2008
→
third iteration of the minor loop.
g) Read byte from location 0x100C, read byte from location 0x100D, read byte from 0x100E,
read byte from 0x100F.
h) Write longword to location 0x200C
→
last iteration of the minor loop
→
major loop complete.
6. The eDMA engine writes: TCD
n
_SADDR = 0x1000, TCD
n
_DADDR = 0x2000, TCD
n
_CITER
= 1 (TCD
n
_BITER).
7. The eDMA engine writes: TCD
n
_CSR[ACTIVE] = 0, TCD
n
_CSR[DONE] = 1, EDMA_INT[
n
]
= 1.
8. The channel retires and the eDMA goes idle or services the next channel.
16.8.4.2
Multiple Requests
Besides transferring 32 bytes via two hardware requests, the next example is the same as previous. The
only fields that change are the major loop iteration count and the final address offsets. The eDMA is
programmed for two iterations of the major loop transferring 16 bytes per iteration. After the channel’s
hardware requests are enabled in EDMA_ERQ, the slave device initiates channel service requests.
TCD
n
_CITER = TCD
n
_BITER = 2
TCD
n
_SLAST = –32
TCD
n
_DLAST_SGA = –32
This would generate the following sequence of events:
1. First hardware (eDMA peripheral) request for channel service.
2. The channel is selected by arbitration for servicing.
3. eDMA engine writes: TCD
n
_CSR[DONE] = 0, TCD
n
_CSR[START] = 0, TCD
n
_CSR[ACTIVE]
= 1.
4. eDMA engine reads: channel TCD
n
data from local memory to internal register file.
5. The source to destination transfers are executed as follows:
a) Read byte from location 0x1000, read byte from location 0x1001, read byte from 0x1002, read
byte from 0x1003.
b) Write longword to location 0x2000
→
first iteration of the minor loop.
c) Read byte from location 0x1004, read byte from location 0x1005, read byte from 0x1006, read
byte from 0x1007.
d) Write longword to location 0x2004
→
second iteration of the minor loop.
e) Read byte from location 0x1008, read byte from location 0x1009, read byte from 0x100A, read
byte from 0x100B.
MCF5329 Reference Manual, Rev 3
Summary of Contents for MCF5329
Page 106: ...ColdFire Core 3 32 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 148: ...Cache 5 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 154: ...Static RAM SRAM 6 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 184: ...Power Management 8 18 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 204: ...Reset Controller Module 10 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 220: ...System Control Module SCM 11 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 228: ...Crossbar Switch XBS 12 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 268: ...General Purpose I O Module 13 40 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 392: ...SDRAM Controller SDRAMC 18 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 436: ...Fast Ethernet Controller FEC 19 44 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 594: ...FlexCAN 23 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 678: ...Pulse Width Modulation PWM Module 26 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 684: ...Watchdog Timer Module 27 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 704: ...DMA Timers DTIM0 DTIM3 29 12 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 754: ...UART Modules 31 34 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 770: ...I2 C Interface 32 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 866: ...Debug Module 36 50 Freescale Semiconductor MCF5329 Reference Manual Rev 3...