21.4.20 E0CSR: USB0 Endpoint0 Control
Bit
7
6
5
4
3
2
1
0
Name
SSUEND
SOPRDY
SDSTL
SUEND
DATAEND
STSTL
INPRDY
OPRDY
Access
RW
RW
RW
R
RW
RW
RW
R
Reset
0
0
0
0
0
0
0
0
Indirect Address: 0x11
Bit
Name
Reset
Access Description
7
SSUEND
0
RW
Serviced Setup End.
Firmware should set this bit to 1 after servicing a setup end (SUEND) event. Hardware clears the SUEND bit when firm-
ware writes 1 to SSUEND.
6
SOPRDY
0
RW
Serviced OPRDY.
Firmware should write 1 to this bit after servicing a received Endpoint 0 packet. The OPRDY bit will
be cleared by a write of 1 to SOPRDY.
5
SDSTL
0
RW
Send Stall.
Firmware can write 1 to this bit to terminate the current transfer (due to an error condition, unexpected transfer request,
etc.). Hardware will clear this bit to 0 when the STALL handshake is transmitted.
4
SUEND
0
R
Setup End.
Hardware sets this read-only bit to 1 when a control transaction ends before firmware has written 1 to the DATAEND bit.
Hardware clears this bit when firmware writes 1 to SSUEND.
3
DATAEND
0
RW
Data End.
Firmware should write 1 to this bit:
1. When writing 1 to INPRDY for the last outgoing data packet.
2. When writing 1 to INPRDY for a zero-length data packet.
3. When writing 1 to SOPRDY after servicing the last incoming data packet.
This bit is automatically cleared by hardware.
2
STSTL
0
RW
Sent Stall.
Hardware sets this bit to 1 after transmitting a STALL handshake signal. This flag must be cleared by firmware.
1
INPRDY
0
RW
IN Packet Ready.
Firmware should write 1 to this bit after loading a data packet into the Endpoint 0 FIFO for transmit. Hardware clears this bit
and generates an interrupt under one of the following conditions:
1. The packet is transmitted.
2. The packet is overwritten by an incoming SETUP packet.
3. The packet is overwritten by an incoming OUT packet.
0
OPRDY
0
R
OUT Packet Ready.
Hardware sets this read-only bit and generates an interrupt when a data packet has been received. This bit is cleared only
when firmware writes 1 to the SOPRDY bit.
This register is accessed indirectly using the USB0ADR and USB0DAT registers.
EFM8UB3 Reference Manual
Universal Serial Bus (USB0)
silabs.com
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