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Section 26 USB 2.0 Host/Function Module
Page 1544 of 2108 R01UH0134EJ0400 Rev. 4.00
Sep 24, 2014
SH7262 Group, SH7264 Group
Refreshing of the frame number and the micro-frame number
SOFR interrupt and SOF lock
Isochronous transfer interval count
If an SOF packet is missing when full-speed operation is being used, the FRNM bit in FRMNUM
is not refreshed. If a SOF packet is missing during high-speed operation, the UFRNM bit in
UFRMNUM is refreshed. However, if a SOF packet for which the UFRNM = 000 is missing, the
FRNM bit is not refreshed. In this case, the FRNM bit is not refreshed even if successive SOF
packets other than UFRNM = 000 are received normally.
26.4.10 Pipe Schedule
(1) Conditions for Generating a Transaction
When the host controller function is selected and UACT has been set to 1, this module generates a
transaction under the conditions noted in table 26.30.
Table 26.30 Conditions for Generating a Transaction
Transaction
Conditions for Generation
DIR PID IITV0 Buffer State SUREQ
Setup *
1
*
1
*
1
*
1
1 setting
Control transfer data stage,
status stage, bulk transfer
IN BUF Invalid Receive
area exists
*
1
OUT BUF Invalid Send data
exists
*
1
Interrupt transfer IN BUF Valid Receive
area exists
*
1
OUT BUF Valid Send data
exists
*
1
Isochronous transfer IN BUF Valid *
2
*
1
OUT BUF Valid *
3
*
1
Notes: 1. Symbols () in the table indicate that the condition is one that is unrelated to the
generating of tokens. "Valid" indicates that, for interrupt transfers and isochronous
transfers, the condition is generated only in transfer frames that are based on the
interval counter. "Invalid" indicates that the condition is generated regardless of the
interval counter.
2. This indicates that a transaction is generated regardless of whether or not there is a
receive area. If there was no receive area, however, the received data is destroyed.
3. This indicates that a transaction is generated regardless of whether or not there is any
data to be sent. If there was no data to be sent, however, a zero-length packet is sent.