37.7.27 USB TX FIFO Size Register
TXFIFOSZ controls the size of the selected TX endpoint FIFO.
| Symbol | Description | Symbol | Description | Symbol | Description |
|---|---|---|---|---|---|
| R | Readable bit | HC | Cleared by Hardware | (Grey cell) | Unimplemented |
| W | Writable bit | HS | Set by Hardware | X | Bit is unknown at Reset |
| K | Write to clear | S | Software settable bit | — | — |
| Name: | TXFIFOSZ |
| Offset: | 0x1062 |
| Reset: | 0x0000 |
| Property: | PAC Write-Protection |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| DPB | FIFOSZ[3:0] | ||||||||
| Access | R/W | R/W | R/W | R/W | R/W | ||||
| Reset | 0 | 0 | 0 | 0 | 0 | ||||
Bit 4 – DPB TX Endpoint Double-packet Buffering Control bit
| Value | Description |
|---|---|
| 0 | Double-packet buffer is not supported |
| 1 | Double-packet buffer is supported. This doubles the size set in TXFIFOSZ. |
Bits 3:0 – FIFOSZ[3:0] TX Endpoint FIFO packet size bits
The maximum packet size to allowed for (before any splitting within the FIFO of Bulk/High-Bandwidth packets prior to transmission)
| Value | Description |
|---|---|
| 1111 | Reserved |
| 1010 | Reserved |
| 1001 | 4096 bytes |
| 1000 | 2048 bytes |
| 0111 | 1024 bytes |
| 0110 | 512 bytes |
| 0101 | 256 bytes |
| 0100 | 128 bytes |
| 0011 | 64 bytes |
| 0010 | 32 bytes |
| 0001 | 16 bytes |
| 0000 | 8 bytes |