GD32F20x User Manual
861
1: The RxDMA uses the RXDP[5:0] bits as burst length while the PGBL[5:0] is used
by TxDMA
22:17
RXDP[5:0]
RxDMA PGBL bits
If UIP=0, these bits are not valid. Only when UIP=1, these bits is configured for the
maximum number of beats to be transferred in one RxDMA transaction.
0x01: max beat number is 1
0x02: max beat number is 2
0x04: max beat number is 4
0x08: max beat number is 8
0x10: max beat number is 16
0x20: max beat number is 32
Other: Reserved
16
FB
Fixed burst bit
0: The AHB can use SINGLE and INCR burst transfer operations
1: The AHB can only use SINGLE, INCR4, INCR8 or INCR16 during start of normal
burst transfers
Note:
MB and FB should be and must be only one of bit is set.
15:14
RTPR[1:0]
RxDMA and TxDMA transfer priority ratio bits
These bits indicate the access ratio between RxDMA and TxDMA.
0x0: RxDMA : TxDMA = 1:1
0x1: RxDMA : TxDMA = 2:1
0x2: RxDMA : TxDMA = 3:1
0x3: RxDMA : TxDMA = 4:1
Note:
This bit is valid only when the arbitration mode is Round-robin (DAB=0)
13:8
PGBL[5:0]
Programmable burst length bits
These bits indicate the maximum number of beats to be transferred in one DMA
transaction. When UIP=1, the PGBL value is only used for TxDMA. When UIP=0,
the PGBL value is used for both TxDMA and RxDMA.
0x01: max beat number is 1
0x02: max beat number is 2
0x04: max beat number is 4
0x08: max beat number is 8
0x10: max beat number is 16
0x20: max beat number is 32
Other: Reserved
7
Reserved
Must be kept at reset value
6:2
DPSL[4:0]
Descriptor skip length bit
These bits are valid only between two ring mode descriptors. They define the
number of words (32-bit) to skip between two unchained descriptors. The address
skipping starts from the end of current descriptor to the start of next descriptor.
Summary of Contents for GD32F20 Series
Page 191: ...GD32F20x User Manual 191 Bits Fields Descriptions 31 0 TRNDATA 31 0 32 Bit Random data ...
Page 290: ...GD32F20x User Manual 290 conversion is ongoing ...
Page 325: ...GD32F20x User Manual 325 15 0 ALRM 15 0 RTC alarm value low ...
Page 385: ...GD32F20x User Manual 385 ...
Page 523: ...GD32F20x User Manual 523 clears AERR bit by writing 0 to it ...