Samsung S3C2500B User Manual page 482

USB CONTROLLER
Bit Number Bit Name
[21] Out mode,
SenD STALL
(OSDSTALL)
[22] Out mode,
SenT STALL
(OSTSTALL)
[23] Out mode, CLear
data TOGgle
(OCLTOG)
[24] In mode, IN packet
ReaDY (IINRDY)
[25] In mode, fifo Not
EMPty (INEMP)
[26] In mode, UNDER
run (IUNDER )
10-42
Table 10-24. USBEP4CSR Register Description (Continued)
MCU
R/W
R/C
R
R/S
R
R/C
USB
R This bit is valid only when endpoint 4 is set to OUT.
The MCU writes a "1" to this bit to issue a STALL
handshake to the USB.
The MCU clears this bit to end the STALL condition
S This bit is valid only when endpoint 4 is set to OUT.
The USB sets this bit when an OUT token is ended
with a STALL handshake.
The USB issues a stall handshake to the host if it
sends more than MAXP data for the OUT token.
S This bit is valid only when endpoint 4 is set to OUT.
When the MCU writes a "1" to this bit, the data
toggle sequence bit is reset to DATA0.
C This bit is valid only when endpoint 4 is set to IN.
The MCU sets this bit, after writing a packet of data
into the 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 the MCU can load the next packet, While this bit
is set , the MCU will not be able to write to the
FIFO.
If the SEND STALL bit is set by the MCU, this bit
can not be set.
S This bit is valid only when endpoint 4 is set to IN.
Indicate there is at least one packet of data in FIFO.
if USBEP4CSR[25:24] is
10 = 1 packet IN FIFO
11 = 2 packets of MAXP =< 1/2 FIFO or
1 packet of MAXP > FIFO size
S This bit is valid only when endpoint 4 is set to IN
ISO.
The USB sets this bit when in ISO mode, an IN
token is received and the IINRDY bit is not set.
The USB sends a zero length data packet for such
conditions, and the next packet that is loaded into
the FIFO is flushed.
S3C2500B
Description