Datasheet

Universal Serial Bus Module (USB)
USB Interrupts
MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Technical Data
Freescale Semiconductor Universal Serial Bus Module (USB) 159
SETUP transactions cannot be stalled by the USB function. A SETUP
received by a control endpoint will clear the ISTALL0 and OSTALL0 bits.
The conditions for receiving a SETUP interrupt are shown in
Figure 9-30.
Figure 9-30. SETUP Token Data Flow for Receive Endpoint 0
ERROR FREE DATA PACKET?
NO RESPONSE
FROM USB FUNCTION
SET RXD0F TO 1
(RXD0IE = 1)
NO INTERRUPT
ACCEPT DATA
N
SET/CLEAR R0SEQ BIT
VALID SETUP TOKEN
RECEIVED FOR ENDPOINT 0?
USB MODULE ENABLED?
(USBEN = 1)
ENDPOINT 0 RECEIVE READY TO RECEIVE?
(RX0E = 1) AND (RXD0F = 0)
RECEIVE CONTROL ENDPOINT
INTERRUPT ENABLED?
VALID TRANSACTION
INTERRUPT GENERATED
NO RESPONSE
FROM USB FUNCTION
NO RESPONSE FROM
USB FUNCTION
IGNORE TRANSACTION
Y
Y
Y
Y
Y
N
N
N
SET SETUP BIT TO 1