Samsung S5PC100 User Manual page 883

USB2.0 HS OTG
8.2.17 Non-Periodic Transmit FIFO/Queue Status Register (GNPTXSTS, R, Address = 0xED20_002C)
This read-only register contains the free space information for the Non-Periodic TxFIFO and the Non-Periodic
Transmit Request Queue.
GNPTXSTS Bit
Reserved [31]
NPTxQTop [30:24] Top of the Non-Periodic Transmit Request Queue.
NPTxQSpcAvail [23:16] Non-Periodic Transmit Request Queue Space Available.
NPTxFSpcAvail [15:0]
8.10 -40
-
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] :
• 2'b00 : IN/ OUT token
• 2'b01 : Zero-length transmit packet (device IN/host OUT)
• 2'b10 : PING/CSPLIT token
• 2'b11 : Channel halt command
• Bit[24] : Terminate (last entry for selected channel/
endpoint)
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.
• 8'h0 : Non-Periodic Transmit Request Queue is full
• 8'h1 : 1 location available
• 8'h2 : 2 locations available
• n : n locations available(0≤n≤8)
• Others : Reserved
Non-Periodic TxFIFO Space Available
Indicates the amount of free space available in the Non-
Periodic TxFIFO.
Values are in terms of 32-bit words.
• 16'h0 : Non-Periodic TxFIFO is full
• 16'h1 : 1 word available
• 16'h2 : 2 words available
• 16'hn : n words available (where 0 ≤ n ≤ 32768)
• 16'h8000 : 32768 words available
• Others : Reserved
Description
S5PC100 USER'S MANUAL (REV1.0)
R/W Reset Value
R
R
R
1'b0
7'h0
8'h08
16'h1800