Figure 18.9 Operation On Receiving An Out Token (Ep5-Out: Initial Fifo Is Full) - Renesas H8S/2158 User Manual

USB Host
Send an OUT
token packet
Send an OUT data
packet (64 bytes)
Receive a NAK
handshake packet
Re-transmission
Send an OUT
token packet
Send an OUT data
packet (64bytes)
Receive an ACK
handshake packet
Notes: 1. When an EP5TF 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 TFFR0 must
be accessed to clear the flags.)
2. 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.)

Figure 18.9 Operation on Receiving an OUT Token (EP5-OUT: Initial FIFO Is Full)

Section 18 Universal Serial Bus Interface (USB)
USB Function Core
Receive an OUT
token packet
Receive an OUT data
packet (64 bytes)
Send NAK to the host CPU
Send NAK to the slave CPU
Receive an OUT
token packet
Receive an OUT data
packet (64 bytes)
Send ACK to the host CPU
Send ACK to the slave CPU
Core Interface
Write data to the EP5
receive buffer
Request RFU transmission
A RAM-FIFO full error
occurs
Request to rewind the
RFU pointer
Request an USBID
interrupt (EP5TF) * 1
Write data to the EP5
receive buffer
Request RFU transmission
Request to modify the RFU
pointer
Request an USBID interrupt
(EP5TS) * 2
Rev. 3.00 Jan 25, 2006 page 613 of 872
Slave CPU
A RAM-FIFO full error
occurs
Rewind the RFU pointer
and send ACK
Initiate the USBID interrupt
processing
Read USBIFR0 and check
if a TF interrupt occurs
or not
Read TFFR0 and check
if an EP5TF interrupt occurs
or not
Read data and modify
the RFU pointer
Clear the EP5TF bit of
TFFR0 to 0
Complete the USBID
interrupt processing
Write data to RAM-FIFO
and send ACK
Modify the RFU pointer
and send ACK
Initiate the USBID
interrupt processing
The following procedure is the same
as that when the initial FIFO is empty.
REJ09B0286-0300