M66596FP/WG
rev .1.00
2006.3.14
page 90 of 127
3.7.2
NYET handshake control in the Peripheral mode
Table 3.23 shows the NYET handshake responses of the controller. The NYET response of the controller is made in
conformance with the conditions noted below. When a short packet is received, however, the response will be an ACK
response rather than a NYET packet response. The same applies to data stages of control write transfers.
Table 3.23 NYET handshake responses
Value set for PID
bit
Buffer memory
state
Token
Response
Note
NAK/STALL
-
SETUP
ACK
-
IN/OUT/PING
NAK/STALL
-
BUF
-
SETUP
ACK
-
RCV-BRDY*1
OUT/PING
ACK
If an OUT token is received, a data packet is
received.
RCV-BRDY*2
OUT
NYET
Notification of whether a data packet is received
or cannot be received
RCV-BRDY*2
OUT (Short)
ACK
Notification of whether a data packet is received
or cannot be received
RCV-BRDY*2
PING
ACK
Notification that reception is not possible
RCV-NRDY
OUT / PING
NAK
Notification that reception is not possible
TRN-BRDY
IN
DATA0 / 1
Data packet transmission
TRN-NRDY
IN
NAK
TRN-NRDY
*1) Buffer memory is state is as following;
RCV-BRDY*1: When an OUT/PING token is received, there is space in the buffer memory for two or more
packets.
RCV-BRDY*2: 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.
3.8 Interrupt transfers(PIPE6-7)
In the Peripheral mode, the controller carries out interrupt transfers in accordance with the timing controlled by
the host controller. For interrupt transfers, PING packets are ignored (no response is sent), and the ACK, NAK and
STALL responses are carried out without an NYET handshake response being made.
In the Host mode, this controller can set up the transmitting timing of a token by interval counter. This controller
does not transmit a PING token at the time of interruption out transmission. When NYET from peripheral is
received, this controller carries out the same operation as ACK reception.
The controller does not support High-Bandwidth transfers of interrupt transfers.