RM0319 datasheet(136/368 Pages) STMICROELECTRONICS

136 / 368 page

USB 2.0 Device ports (UDC)

RM0319

136/368

Doc ID 022640 Rev 3

Figure 43.

In data memory

Table 40.

In data memory: buffer status quadlet bit assignments (for non-

isochronous IN)

Bit

Name

Description

[31:30]

Buffer status.

This 2 bit field reports the status of the in buffer, according to encoding:

– 2’b00, Host ready. The descriptor is available to be processed by DMA.

– 2'b01, DMA busy. The DMA is still processing the descriptor.

– 2'b10, DMA done. Buffer data transfer completed by DMA.

– 2'b11, Host busy. The application is processing the descriptor.

[29:28]

Tx Sts

Transmit status.

This 2 bit field reports the status of the transmitted in data (according to

encoding), reflecting whether the in data has been correctly transmitted or

some errors occurred:

– 2'b00 = Success.

– 2'b01 = DESERR (descriptor transfer error).

– 2'b10 = Reserved.

– 2'b11 = BUFFER (data transfer error).

[27]

If set, it indicates that this descriptor is the last one of the chain.

[26:16]

Reserved

Read: undefined. Write: should be zero.

[15:00]

Tx Bytes

Number of bytes to be transmitted.

Its 16 bit width allows values ranging from 0 to 64 kbytes. for iso in

transactions, a maximum value of 16 kbytes is allowed by the 14 bit length

of the Tx bytes field.

Data Descriptor Pointer

IN Buffer Status Quadlet

Reserved

Buffer Pointer

Next Descriptor Pointer

Status Quadlet for

Non Iso-chronous IN

TxBytes

Tx Sts

15:0

26:16

29:28

31:30

Status Quadlet for

Iso-chronous IN

Frame Number

TxBytes

Tx Sts

13:0

26:16

29:28

31:30

PID

15:14

RM0319 датащи(PDF) 136 Page - STMicroelectronics

RM0319 датащи(HTML) 136 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL