Datasheet

8−20
SLLS535E − April 2008TUSB6250
8.10.8 IEPBCNHY_n: Input Endpoint Y-Buffer Byte-Count High-Byte Register (n = 1
to 4) (XDATA at F017, F027, F037, F047)
The IEPBCNHY_n register contains the NAK bit and the higher 3-bit value in the Y-buffer that is used to specify
the amount of data to be transmitted in a data packet to the USB host. See the procedure described in the
IEPBCNHX_n register when using the NAK bit for flow control handshake.
76543210
NAK RSV RSV RSV RSV C10 C9 C8
R/W R/O R/O R/O R/O R/W R/W R/W
BIT
NAME RESET FUNCTION
2−0 C[10:8] 000 Y-buffer byte count higher 3 bits. These bits, in combination with C[7:0], provide the byte count of a
given transaction (count = 0 to 2047).
6−3 RSV 0000 Reserved = 0
7 NAK 0 NAK bit is used as flow control handshake for Y-buffer.
NAK = 0 Buffer contains a valid packet for the Host-IN request.
NAK = 1 Buffer is empty (TUSB6250 NAKs the host-IN request).
8.10.9 OEPCNF_n: Output Endpoint Configuration Register (n = 1 to 4) (XDATA at
F018, F028, F038, F048)
The OEPCNF_n register contains various bits used to configure and control the specified endpoint.
76543210
UBME NAK_INTE TOGLE DBUF STALL USBIE RS_TOGLE MAP_SECF
R/W R/W R/O R/W R/W R/W W/O R/W
BIT
NAME RESET FUNCTION
0 MAP_SECF 0 Map data buffer to sector FIFO RAM. The MCU writes to this bit to inform the state machine
whether it wants the data to be transferred/stored in either the 4K-byte EDB buffer or the sector
FIFO. If the sector FIFO is selected, when the data transfer phase is over, the state machine
automatically switches the data storage area back to the 4K-byte EDB buffer.
MAP_SECF = 0 Endpoint data is stored in the 4K-byte endpoint data buffer.
MAP_SECF = 1 Endpoint data is stored in the sector FIFO RAM.
1 RST_TOGLE 0 Reset TOGLE. This bit always returns 0 when read by the MCU.
The MCU can write a 1 to this bit in order to reset the TOGLE bit (bit 5) to ‘0’.
2 USBIE 0 USB interrupt enable on transaction completion. Set/cleared by the MCU.
USBIE = 0 No interrupt
USBIE = 1 Interrupt on transaction completion
3 STALL 0 USB stall condition indication.
STALL = 0 No stall
STALL = 1 USB stall condition. If set by the MCU, a STALL handshake is initiated.
4 DBUF 0 Double buffer enable for output endpoint_n.
DBUF = 0 Primary buffer only (X-buffer only)
DBUF = 1 TOGLE-bit selects X- or Y-buffer.
5 TOGLE 0 USB toggle bit. This read-only bit reflects the toggle sequence bit of DATA0, DATA1. The actual
response from the TUSB6250 depends on the related STALL and NAK bits. The hardware
updates the TOGLE bit automatically.
TOGLE = 0 The TUSB6250 expects the next out-transfer data packet PID to be DATA0.
TOGLE = 1 The TUSB6250 expects the next out-transfer data packet PID to be DATA1.
6 NAK_INTE 0 NAK interrupt enable
NAK_INTE = 0 NAK does not trigger an interrupt.
NAK_INTE = 1 NAK triggers an interrupt.
7 UBME 0 UBM enable/disable bit. Set/cleared by the MCU.
UBME = 0 UBM cannot use this endpoint.
UBME = 1 UBM can use this endpoint.