NXP Semiconductors Kinetis KE1xZ256, Reference Manual

Page: 255 / 1325

This generates the following event sequence:
1. User write to the TCDn_CSR[START] bit requests channel service.
2. The channel is selected by arbitration for servicing.
3. eDMA engine writes: TCDn_CSR[DONE] = 0, TCDn_CSR[START] = 0,
TCDn_CSR[ACTIVE] = 1.
4. eDMA engine reads: channel TCD 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 32-bits 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 32-bits 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 32-bits 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 32-bits to location 0x200C
→
last iteration of the minor loop
→
major loop
complete.
6. The eDMA engine writes: TCDn_SADDR = 0x1000, TCDn_DADDR = 0x2000,
TCDn_CITER = 1 (TCDn_BITER).
7. The eDMA engine writes: TCDn_CSR[ACTIVE] = 0, TCDn_CSR[DONE] = 1,
INT[n] = 1.
8. The channel retires and the eDMA goes idle or services the next channel.
Chapter 13 Enhanced Direct Memory Access (eDMA)
Kinetis KE1xZ256 Sub-Family Reference Manual, Rev. 3, 07/2018
NXP Semiconductors 255