Datasheet

© 2011-2014 Microchip Technology Inc. DS60001168F-page 133
PIC32MX1XX/2XX
REGISTER 10-10: U1STAT: USB STATUS REGISTER
Bit
Range
Bit
31/23/15/7
Bit
30/22/14/6
Bit
29/21/13/5
Bit
28/20/12/4
Bit
27/19/11/3
Bit
26/18/10/2
Bit
25/17/9/1
Bit
24/16/8/0
31:24
U-0 U-0 U-0 U-0 U-0 U-0 U-0 U-0
— — — — — — — —
23:16
U-0 U-0 U-0 U-0 U-0 U-0 U-0 U-0
— — — — — — — —
15:8
U-0 U-0 U-0 U-0 U-0 U-0 U-0 U-0
— — — — — — — —
7:0
R-x R-x R-x R-x R-x R-x U-0 U-0
ENDPT<3:0> DIR PPBI — —
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 31-8 Unimplemented: Read as ‘0’
bit 7-4 ENDPT<3:0>: Encoded Number of Last Endpoint Activity bits
(Represents the number of the Buffer Descriptor Table, updated by the last USB transfer.)
1111 = Endpoint 15
1110 = Endpoint 14
•
•
•
0001 =Endpoint 1
0000 =Endpoint 0
bit 3 DIR: Last Buffer Descriptor Direction Indicator bit
1 = Last transaction was a transmit (TX) transfer
0 = Last transaction was a receive (RX) transfer
bit 2 PPBI: Ping-Pong Buffer Descriptor Pointer Indicator bit
1 = The last transaction was to the ODD Buffer Descriptor bank
0 = The last transaction was to the EVEN Buffer Descriptor bank
bit 1-0 Unimplemented: Read as ‘0’
Note: The U1STAT register is a window into a 4-byte FIFO maintained by the USB module. U1STAT value is only
valid when the TRNIF (U1IR<3>) bit is active. Clearing the TRNIF bit advances the FIFO. Data in register
is invalid when the TRNIF bit = 0.