PDIUSBD12
USB interface device with parallel bus
Philips Semiconductors
The arrival of a SETUP packet flushes the IN buffer and disables the Validate Buffer
and Clear Buffer commands for both IN and OUT endpoints.
The microcontroller needs to re-enable these commands by the Acknowledge Setup
command. This ensures that the last SETUP packet stays in the buffer and no packet
can be sent back to the host until the microcontroller has acknowledged explicitly that
it has seen the SETUP packet.
The microcontroller must send the Acknowledge Setup command to both the IN and
OUT endpoints.
11.4 General commands
11.4.1 Send resume
Code (Hex) — F6
Transaction — none
Sends an upstream resume signal for 10 ms. This command is normally issued when
the device is in suspend. The RESUME command is not followed by a data read or
write.
11.4.2 Read current frame number
Code (Hex) — F5
Transaction — read 1 or 2 bytes
This command is followed by one or two data reads and returns the frame number of
the last successfully received SOF. The frame number is returned Least Significant
byte first.
Fig 15. Read current frame number.
9397 750 09238
© Koninklijke Philips Electronics N.V. 2001. All rights reserved.
Product data
Rev. 08 — 20 December 2001
21 of 35
NXP [ NXP ]
