PDIUSBD12D NXP Semiconductors, PDIUSBD12D Datasheet - Page 22

• Manufacturer Part Number: PDIUSBD12D
• Description: USB Interface IC USB INTRFC W/PARL BUS
• Manufacturer: NXP Semiconductors

Specifications of PDIUSBD12D

• Operating Supply Voltage: 4 V to 5.5 V
• Lead Free Status / Rohs Status: Details
• Other names: PDIUSBD12D,112

Philips Semiconductors
PDIUSBD12_9
Product data sheet
11.3.10 Acknowledge Setup
11.3.8 Validate Buffer
11.3.9 Set Endpoint Status
When a packet is completely received, an internal endpoint buffer full flag is set. All
subsequent packets will be refused by returning a NAK. When the microcontroller has
read data, it should free the buffer using the Clear Buffer command. When the buffer is
cleared, new packets will be accepted.
Code (Hex) — FA
Transaction — none
When the microprocessor has written data into an IN buffer, it should set the buffer full flag
using the Validate Buffer command. This indicates that data in the buffer is valid and can
be sent to the host when the next IN token is received.
Code (Hex) — 40 to 45
Transaction — write 1 B
A stalled control endpoint is automatically un-stalled when it receives a SETUP token,
regardless of the content of the packet. If the endpoint should stay in its stalled state, the
microcontroller can re-stall it.
When a stalled endpoint is un-stalled (either by the Set Endpoint Status command or by
receiving a SETUP token), it is also re-initialized. This flushes the buffer and if it is an OUT
buffer it waits for a DATA0 PID, if it is an IN buffer it writes a DATA0 PID.
Even when un-stalled, writing logic 0 to Set Endpoint Status initializes the endpoint.
Code (Hex) — F1
Transaction — none
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 using 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.
Fig 14. Set Endpoint Status: bit allocation
STALLED: Logic 1 indicates the endpoint is stalled.
Rev. 09 — 11 May 2006
X X
7 6 5 4 3 2
X X
X X
X
1
USB peripheral controller with parallel bus
0
0
Power-on value
STALLED
reserved
004aaa806
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
PDIUSBD12
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