Datasheet

8−19
SLLS535E − April 2008 TUSB6250
5. Once the USB host acknowledges the host-IN transfer with an ACK, the TUSB6250 hardware sets the
NAK bit to 1, so that any new host-IN request is NAKed until the MCU and firmware get the new required
data payload ready.
8.10.5 IEPSIZXY_n: Input Endpoint X/Y-Buffer Size Register (n = 1 to 4) (XDATA at
F014, F024, F034, F044)
The IEPSIZXY register contains the X- and Y-buffer size for the specified input endpoint.
76543210
S10 S9 S8 S7 S6 S5 S4 S3
R/W R/W R/W R/W R/W R/W R/W R/W
BIT
NAME RESET FUNCTION
7−0 S[10:3] 00h X- and Y-buffer size in byte: S[2:0] is padded with zeros (S[10:3] & 000) to produce an 11-bit value.
Size is 0 to 1024 in increments of eight.
8.10.6 IEPBBADRY_n: Input Endpoint Y-Buffer Base Address Register (n = 1 to 4)
(XDATA at F015, F025, F035, F045)
The IEPBBADRY_n register contains the Y-buffer base address for the specified input endpoint.
76543210
A11 A10 A9 A8 A7 A6 A5 A4
R/W R/W R/W R/W R/W R/W R/W R/W
BIT
NAME RESET FUNCTION
7−0 A[11:4] 00h This is the middle 8-bit value of the complete (1110 & A[11:4] & 0000) 16-bit Y-buffer base address.
See Figure 8−4. This value is set by the MCU. The UBM or the MCU uses this value as the start
address of the Y-buffer for a given transaction.
8.10.7 IEPBCNLY_n: Input Endpoint Y-Buffer Byte-Count Low-Byte Register (n = 1 to
4) (XDATA at F016, F026, F036, F046)
The IEPBCNLY_n register contains the lower 8-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.
76543210
C7 C6 C5 C4 C3 C2 C1 C0
R/W R/W R/W R/W R/W R/W R/W R/W
BIT
NAME RESET FUNCTION
7−0 C[7:0] 00h Y-buffer byte-count: low byte