S3C4530A Datasheet, PDF (313/432 Pages) Samsung semiconductor – 16/32-bit RISC microcontroller is a cost-effective, high-performance microcontroller

S3C4530A
HDLC CONTROLLERS
BUFFER DESCRIPTOR
TRANSMIT BUFFER DESCRIPTOR
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
O
Buffer Data Pointer
Reserved
WA D L E N P
Reserved T
Buffer Length
Next Buffer Descriptor Pointer
[30:0] Buffer Data Pointer
[31] Ownership (O)
0 = CPU
1 = DMA
Tx Control Bits
[0] Preamble (P)
0 = No preamble
1 = Preamble
[1] TxNO CRC Mode (N)
0 = CRC mode
1 = No CRC mode
[2] Little-Endian Mode (E)
0 = Big-Endian
1 = Little-Endian
[3] Last (L)
0 = This is not the last buffer in the frame.
1 = This is the last buffer inth frame.
[4] Buffer Data Pointer Decrement (D)
0 = Increment
1 = Decrement
[6:5] Widget Aligment Control (WA)
00 = No invalid bytes
01 =1 invalid bytes
10 = 2 invalid bytes
11 = 3 invalid bytes
[23:0] Buffer Lenght
Tx Status Bit
This bit may be regarded as valid when the L bit (in Tx control bit) is set.
[26] Transmission Completion (T)
0 = Normal
1 = One frame completed
[31:0] Next Buffer Descriptor Pointer
The address of the next buffer descriptor
Figure 8-10. Transmit Buffer Descriptor
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