Cypress FM4 Series - Descriptor 2 (DES2); Descriptor 3 (DES3)

CHAPTER 11: DSTC
578 FM4 Peripheral Manual, Doc. No. 002-04856 Rev. *E
5.15 Descriptor 2 (DES2)
This section explains details of Descriptor 2 (DES2).
DES2 Descriptor configuration
Address: DESTP + DESP + 0x08
bit
31
0
Field
SA[31:0]
C attribute
R/W
D attribute
R/W
DES2 Descriptor function
bit[31:0] SA[31:0] (Source address)
The SA[31:0] bits set the transfer source address. The SA[31:0] bits cannot be set to a value unaligned to
the data size specified in DES0:TW. The DSTC updates the value of DES3 when writing back values to
the DES. If OuterReload of DES2 is enabled (ORL[1] = 1), the DSTC copies the value of DES5 to DES2.
Pay attention to the value at the end of a transfer if InnerReload/OuterReload of the transfer source
address is not enabled. If the transfer ends in the form of error, the DSTC stores the value appearing
before the end of the transfer, and in turn, it is necessary to initialize the SA[31:0] bits via the CPU.
5.16 Descriptor 3 (DES3)
This section explains details of Descriptor 3 (DES3).
DES3 Descriptor configuration
Address: DESTP + DESP + 0x0C
bit
31
0
Field
DA[31:0]
C attribute
R/W
D attribute
R/W
DES3 Descriptor function
bit[31:0] DA[31:0] (Destination Address)
The DA[31:0] bits set the transfer destination address. The DA[31:0] bits cannot be set to a value
unaligned to the data size specified in DES0:TW. The DSTC updates the value of DES3 when writing
back values to the DES. If OuterReload of DES3 is enabled (ORL[2] = 1), the DSTC copies the value of
DES6 to DES3. Pay attention to the value at the end of a transfer if InnerReload/OuterReload of the
transfer destination address is not enabled. If the transfer ends in the form of error, the DSTC stores the
value appearing before the end of the transfer, and in turn, it is necessary to initialize the DA[31:0] bits via
the CPU.