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Section 26 USB 2.0 Host/Function Module
R01UH0134EJ0400 Rev. 4.00 Page 1491 of 2108
Sep 24, 2014
SH7262 Group, SH7264 Group
Figure 26.4 shows the timing at which an NRDY interrupt is generated when the function
controller function is selected.
IN Token Packet
OUT Token Packet
NAK Handshake
Data Packet
PING Packet NAK Handshake
*1 In isochronous transfer, Handshake is not transmitted.
*2 The PIPENRDY bit is changed to 1 only when the PID bit for the pertinent pipe is to 1.
*3 The CRC and OVRN bits are changed only when the transfer type for the pertinent pipe is isochronous transfer.
(1) Data transmission (in single buffer mode)
USB bus
Buffer memory status
Writing enabled state (there is no data to be transmitted)
NRDY interrupt
(corresponding
PIPENRDY bit is
changed)*2
(2) Data reception: OUT token reception (in single buffer mode)
USB bus
Buffer memory status
Reading enabled state (there is no reception enabled area)
NRDY interrupt
(corresponding
PIPENRDY bit is
changed)*2
(CRC bit, etc.)*3
(3) Data reception: PING token reception (in single buffer mode)
USB bus
Buffer memory status
Reading enabled state (there is no reception enabled area)
NRDY interrupt
(corresponding
PIPENRDY bit is
changed)*2
Packet transmitted by the host
Packet transmitted by the peripheral module
*1
*1
NAK Handshake
Figure 26.4 Timing at which NRDY Interrupt is Generated when Function Controller
Function is Selected