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Section 26 USB 2.0 Host/Function Module
R01UH0134EJ0400 Rev. 4.00 Page 1529 of 2108
Sep 24, 2014
SH7262 Group, SH7264 Group
(2) NYET Handshake Control when the Function Controller Function is Selected
Table 26.26 lists the responses to received tokens during bulk transmission and control
transmission. The USB 2.0 host/function module returns a NYET when an OUT token is received
while there is only one packet of empty space in the buffer memory, during both bulk transmission
and control transmission. However, an ACK is returned instead of a NYET even under the above
conditions when a short packet is received.
Table 26.26 List of Responses to Received Tokens
Value Set
for PID Bit in
DCPCTR
Buffer
Memory
State Token Response Note
NAK/STALL SETUP ACK
IN/OUT/
PING
NAK/STALL
BUF SETUP ACK
RCV-BRDY1 OUT/PING ACK If an OUT token is received, a data
packet is received.
RCV-BRDY2 OUT NYET Notifies whether a data packet can
be received
RCV-BRDY2 OUT (Short) ACK Notifies whether a data packet can
be received
RCV-BRDY2 PING ACK Notifies that a data packet can be
received
RCV-NRDY OUT/PING NAK Notifies that a data packet cannot be
received
TRN-BRDY IN DATA0/DATA1 A data packet is transmitted
TRN-NRDY IN NAK Notifies that a data packet cannot be
transmitted
[Legend]
RCV-BRDY1: When an OUT/PING token is received, there is space in the buffer memory for two
or more packets.
RCV-BRDY2: When an OUT token is received, there is only enough space in the buffer memory
for one packet.
RCV-NRDY: When a PING token is received, there is no space in the buffer memory.
TRN-BRDY: When an IN token is received, there is data to be sent in the buffer memory.
TRN-NRDY: When an IN token is received, there is no data to be sent in the buffer memory.