gnptxsts

In Device mode, this register is valid only in Shared FIFO operation. It contains the free space information for the Non-periodic TxFIFO and the Nonperiodic Transmit RequestQueue

Module Instance	Base Address	Register Address
`usb0`	`0xFFB00000`	`0xFFB0002C`
`usb1`	`0xFFB40000`	`0xFFB4002C`

Offset: 0x2C

Access: RO

Important: To prevent indeterminate system behavior, reserved areas of memory must not be accessed by software or hardware. Any area of the memory map that is not explicitly defined as a register space or accessible memory is considered reserved.

Bit Fields
31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16
`Reserved`	`nptxqtop` `RO 0x0`							`nptxqspcavail` `RO 0x8`
15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
`nptxfspcavail` `RO 0x400`

gnptxsts Fields

Bit

Name

Description

Access

Reset

30:24

nptxqtop

Entry in the Non-periodic Tx Request Queue that is currently being processed by the MAC. -Bits [30:27]: Channel/endpoint number -Bits [26:25]: -Bit [24]: Terminate (last Entry for selected channel endpoint)

Value	Description
0x0	IN/OUT token
0x1	Zero-length transmit packet (device IN/host OUT)
0x2	PING/CSPLIT token
0x3	Channel halt command

RO

0x0

23:16

nptxqspcavail

Indicates the amount of free space available in the Non-periodic Transmit Request Queue. This queue holds both IN and OUT requests in Host mode. Device mode has only IN requests. -Others: Reserved

Value	Description
0x0	Non-periodic Transmit Request Queue is full
0x1	1 location available
0x2	2 locations available
0x3	3 locations available
0x4	4 locations available
0x5	5 locations available
0x6	6 locations available
0x7	7 locations available
0x8	8 locations available

RO

0x8

15:0

nptxfspcavail

Indicates the amount of free space available in the Non-periodic TxFIFO.Values are in terms of 32-bit words. 16h0: Non-periodic TxFIFO is full 16h1: 1 word available 16h2: 2 words available 16hn: n words available (where 0 n 32,768) 16h8000: 32,768 words available Others: Reserved

RO

0x400