Endpoint Valid Size Registers 0S, 0O, 0I, 1, 2, And 3 (Fvsr0S, Fvsr0O, Fvsr0I, Fvsr1, Fvsr 2, And Fvsr3) - Renesas H8S/2158 User Manual

Section 18 Universal Serial Bus Interface (USB)
EPDR0I
Bit Bit Name Initial Value R/W
7 to 0 D7 to D0 All 0
EPDR1
Bit Bit Name Initial Value R/W
7 to 0 D7 to D0 All 0
EPDR2
Bit Bit Name Initial Value R/W
7 to 0 D7 to D0 All 0
EPDR3
Bit Bit Name Initial Value R/W
7 to 0 D7 to D0 All 0
18.3.4 Endpoint Valid Size Registers 0S, 0O, 0I, 1, 2, and 3 (FVSR0S, FVSR0O, FVSR0I,
FVSR1, FVSR 2, and FVSR3)
FVSRs indicate the number of valid data items stored in FIFOs in each endpoint of the USB
function core. Since endpoints 4 and 5 do not use FIFOs in the USB interface, they perform data
transfer by using the RFU which has the function corresponding to FVSRs.
In host input transfer, FVSR indicates the number of bytes that the slave CPU can write to the
FIFO (FIFO size — number of bytes that are written to the FIFO by the slave CPU but which are
not read (transmitted) by the USB function core). In host output transfer, FVSRs indicate the
number of bytes that are written to the FIFO by the USB function core but which are not read by
the slave CPU.
Rev. 3.00 Jan 25, 2006 page 560 of 872
REJ09B0286-0300
Description
W Endpoint 0 is used for input or output transfer and
EPDR0I is specified as a write-only register.
Description
W Endpoint 1 is used for input transfer and EPDR1 is
specified as a write-only register.
Description
R or W EPDR2 is specified as a write-only or read-only
register depending on the transfer direction specified
by EPDIR0.
Description
W Endpoint 3 is used for input transfer and EPDR3 is
specified as a write-only register.