Sharp LH79524 - Control Status Register 1 for in EP 1, 2, and 3 (INCSR1); Table 17-30. INCSR1 Register; Table 17-31. INCSR1 Fields

LH79524/LH79525 User’s Guide Universal Serial Bus Device
Version 1.0 17-23
17.2.3.4 Control Status Register 1 for IN EP 1, 2, and 3 (INCSR1)
The INCSR1 register maintains the control and status bits for IN endpoints. Software
should only access this register for an IN endpoint after the endpoint has been configured
via INCSR2. The INDEX register must be used to write and read INCSR1.
Table 17-30. INCSR1 Register
BIT 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
FIELD ///
RESET 0000000000000000
RW RO RO RO RO RO RO RO RO RO RO RO RO RO RO RO RO
BIT 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
FIELD ///
CLRTOG
SENT_STALL
SEND_STALL
FIFO_FLUSH
UNDERRUN
FIFO_NE
IN_PKT_RDY
RESET 0000000000000000
TYPE RO RO RO RO RO RO RO RO RO RW RW RW RW RW RW RW
ADDR
0xFFFF5000 + 0x044
(with the INDEX register set to IN endpoint 1, 2, or 3)
Table 17-31. INCSR1 Fields
BITS NAME FUNCTION
31:7
/// Reserved Reading returns 0. Write the reset value.
6CLRTOG
Clear Data Toggle The Serial Interface Engine (SIE) toggles the Data
PID sequence identifier for USB transactions with multiple data packets.
In the case of an error condition that requires the USB transaction to be
re-synchronized, this bit must be programmed to 1 by software to reset
the data toggle so that the SIE will transmit a DATA0 packet identifier on
the succeeding transfer. This bit is automatically cleared to 0 when the
USB Device reads it.
1 = Data Toggle bit cleared
0 = No effect on Data Toggle
5 SENT_STALL
STALL Send Acknowledge The USB block programs this bit to 1 when
a STALL handshake is issued to an IN token by the USB Host, in re-
sponse to software programming the SEND_STALL bit to 1. When the
USB issues a STALL handshake, IN_PKT_RDY is cleared to 0. Clear this
bit by writing a 0 to it.
1 = STALL handshake issued by USB to an in IN token in response to
software setting the SEND_STALL bit
0 = Normal operation
4 SEND_STALL
Send STALL Handshake to USB Software must program this bit to 1
to issue a STALL handshake to the next IN token. The USB reads the bit
and issues a STALL handshake. Software must program the bit to 0 to
end the STALL condition.
1 = Issue a STALL handshake to the USB Host
0 = End the STALL condition