GD32F20x User Manual
828
RB2AP/RTSH[31:16]
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
RB2AP/RTSH[15:0]
rw
Bits
Fields
Descriptions
31:0
RB2AP/RTSH[31:0]
Receive buffer 2 address pointer (next descriptor address) / Receive frame
timestamp high 32-bit value bits
These bits are designed for two different functions: buffer address pointer or next
descriptor address (RB1AP) or timestamp high 32-bit value (RTSH).
RB2AP
: Before fetching this descriptor by RxDMA controller, these bits are
configured to the buffer 2 address (RCHM=0) or the next descriptor address
(RCHM=1) by application. This buffer 2 address pointer is used for RxDMA
controller to store the received frame if RB1S is not 0 when RCHM=0. If RCHM=1
and RERM=0, this address pointer is used for fetching the next descriptor. If
RCHM=1 and RERM=1, these bits are ignored.
When this address is used for next descriptor address, the word alignment is
needed. The other conditions have no limitation for these bits.
RTSH
: When timestamp function is enabled and LDES is set, these bits will be
changed to timestamp high 32-bit value by RxDMA controller if received frame
passed the filter and satisfied the snapshoot condition. If the received frame does
not meet the snapshoot condition, these bits will keep RB2AP value.
27.3.7.
Example for a typical configuration flow of Ethernet
After power-on reset or system reset, the following operation flow is a typical process for
application to configure and run Ethernet:
Enable Ethernet clock.
Program the RCU module to enable the HCLK and Ethernet Tx/Rx clock.
Setup the communication interface.
Configure AFIO_PCF0 to define which interface mode is selected (MII or RMII).
Configure GPIO module to make selected PADs to alternate function.
Wait the resetting complete
Polling the ENET_DMA_BCTL register until the SWR bit is reset. (SWR bit is set by
default after power-on reset or system reset)
Obtain and configure the parameters in PHY register
According to the frequency of HCLK, configure the SMI clock frequency and access
external PHY register to obtain the information of PHY (e.g. support Half/Full duplex or
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 ...