Samsung S3C2440A User Manual
Page 341
S3C2440A RISC MICROPROCESSOR
USB DEVICE
13-13
END POINT0 CONTROL STATUS REGISTER (EP0_CSR)
This register has the control and status bits for Endpoint 0. Since a control transaction is involved with both IN and
OUT tokens, there is only one CSR register, mapped to the IN CSR1 register. (Share IN1_CSR and can access by
writing index register “0” and read/write IN1_CSR)
Register Address R/W
Description
Reset
Value
EP0_CSR 0x52000184(L)
0x52000187(B)
R/W
(byte)
Endpoint 0 status register
0x00
EP0_CSR Bit
MCU
USB
Description
Initial
State
SERVICED_SE
TUP_END
[7]
W
CLEAR
The MCU should write a "1" to this bit to clear
SETUP_END.
0
SERVICED_OU
T_PKT_RDY
[6]
W
CLEAR
The MCU should write a "1" to this bit to clear
OUT_PKT_RDY.
0
SEND_STALL
[5]
R/W
CLEAR
MCU should write a "1" to this bit at the same time it clears
OUT_PKT_RDY, if it decodes an invalid token.
0 = Finish the STALL condition
1 = The USB issues a STALL and shake to the
current control transfer.
0
SETUP_END
[4]
R
SET
Set by the USB when a control transfer ends before
DATA_END is set.
When the USB sets this bit, an interrupt is generated to
the MCU.
When such a condition occurs, the USB flushes the FIFO
and invalidates MCU access to the FIFO.
0
DATA_END
[3]
SET
CLEAR
Set by the MCU on the conditions below:
1. After loading the last packet of data into the FIFO, at the
same time IN_PKT_RDY is set.
2. While it clears OUT_PKT_RDY after unloading the last
packet of data.
3. For a zero length data phase.
0
SENT_STALL [2]
CLE
AR
SET
Set by the USB if a control transaction is stopped due to a
protocol violation. An interrupt is generated when this bit is
set. The MCU should write "0" to clear this bit.
0
IN_PKT_RDY
[1]
SET
CLEAR
Set by the MCU after writing a packet of data into EP0
FIFO. The USB clears this bit once the packet has been
successfully sent to the host. An interrupt is generated
when the USB clears this bit, so as the MCU to load the
next packet. For a zero length data phase, the MCU sets
DATA_END at the same time.
0
OUT_PKT_RDY
[0]
R
SET
Set by the USB once a valid token is written to the FIFO.
An interrupt is generated when the USB sets this bit. The
MCU clears this bit by writing a "1" to the
SERVICED_OUT_PKT_RDY bit.
0