Samsung S5PC100, User Manual

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USB2.0 HS OTG S5PC100 USER’S MANUAL (REV1.0)
8.10 -40
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 Description R/W Reset Value
Reserved [31] - 1'b0
NPTxQTop [30:24] Top of the Non-Periodic Transmit Request Queue.
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)
R 7'h0
NPTxQSpcAvail [23:16] Non-Periodic Transmit Request Queue Space Available.
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
R 8'h08
NPTxFSpcAvail [15:0] 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
R 16'h1800