SH7764 Datasheet, PDF (980/1752 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC Engine Family SH-4A Series

Section 21 USB 2.0 Host/Function Module (USB)
Bit
Bit Name
1, 0
PID[1:0]
Initial
Value R/W
00
R/W
Description
Response PID
Specifies the response type for the next transaction
of the pertinent pipe.
00: NAK response
01: BUF response (depending on the buffer state)
10: STALL response
11: STALL response
The default setting of these bits is NAK. Modify the
setting to BUF to use the pertinent pipe for USB
transfer. Tables 21.13 and 21.14 show the basic
operation (operation when there are no errors in the
transmitted and received packets) of this module
depending on the PID bit setting.
After modifying the setting of these bits through
software from BUF to NAK during USB
communication using the pertinent pipe, check that
PBUSY is 1 to see if USB communication using the
pertinent pipe has actually entered the NAK state.
However, if the PID bits have been modified to NAK
by this module, checking PBUSY through software is
not necessary.
This module modifies the setting of these bits as
follows.
• This module sets PID to NAK on recognizing the
completion of the transfer when the pertinent pipe
is in the receiving direction and software has set
the SHTNAK bit for the selected pipe to 1.
• This module sets PID to STALL (11) on receiving
the data packet with the payload exceeding the
maximum packet size of the pertinent pipe.
• This module sets PID to NAK on detecting a USB
bus reset when the function controller function is
selected.
Rev. 1.00 Nov. 22, 2007 Page 924 of 1692
REJ09B0360-0100