Figure 18.8 Operation On Receiving An Out Token (Ep5-Out: Initial Fifo Is Empty) - Renesas H8S/2158 User Manual

Section 18 Universal Serial Bus Interface (USB)
USB Host
Send an OUT
token packet
Send an OUT data
packet (64 bytes)
Receive an ACK
handshake packet
Notes: 1. When an EP5TS interrupt is specified as a USBIB or USBIC interrupt according to the INTSELR0 setting, the corresponding
interrupt occurs. In this case, if a USBIB or USBIC interrupt occurs, interrupt source determination process is not required.
(Note that TSFR0 must be accessed to clear the flags.)
2. If the RAM-FIFO size is increased (defined as larger size), the pointer need not be modified after each data processing.

Figure 18.8 Operation on Receiving an OUT Token (EP5-OUT: Initial FIFO Is Empty)

Rev. 3.00 Jan 25, 2006 page 612 of 872
REJ09B0286-0300
USB Function Core
Receive an OUT
token packet
Receive an OUT data
packet (64 bytes)
Send ACK to the host
Send ACK to
the slave CPU
Core Interface
Write data to the EP5
receive buffer
Request RFU
transmission
Request to modify
the RFU pointer
Request an USBID
interrupt (EP5TS) * 1
Slave CPU
Read the receive buffer,
write data to RAM-FIFO,
and send ACK
Modify the RFU pointer
and send ACK
Initiate the USBID interrupt
processing
Read USBIFR0 and check
if a TS interrupt occurs
or not
Read TSFR0 and check
if an EP5TS interrupt occurs
or not
Read the RFU pointer and
check if the EP5 RAM-FIFO
contains 64-byte data
Process RAM-FIFO data
Modify the RFU pointer * 2
Clear the EP5TS bit of
TSFR0 to 0
Complete the USBID
interrupt processing