MC68HC908JB8 Datasheet, PDF (159/286 Pages) Motorola, Inc – MICROCONTROLLERS

Universal Serial Bus Module (USB)
USB Interrupts
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.
VALID SETUP TOKEN
RECEIVED FOR ENDPOINT 0?
Y
USB MODULE ENABLED?
N
(USBEN = 1)
Y
ENDPOINT 0 RECEIVE READY TO RECEIVE? N
(RX0E = 1) AND (RXD0F = 0)
Y
NO RESPONSE
FROM USB FUNCTION
NO RESPONSE
FROM USB FUNCTION
ACCEPT DATA
SET/CLEAR R0SEQ BIT
SET SETUP BIT TO 1
N
ERROR FREE DATA PACKET?
Y
SET RXD0F TO 1
IGNORE TRANSACTION
NO RESPONSE FROM
USB FUNCTION
RECEIVE CONTROL ENDPOINT
N
INTERRUPT ENABLED?
(RXD0IE = 1)
Y
VALID TRANSACTION
INTERRUPT GENERATED
NO INTERRUPT
Figure 9-30. SETUP Token Data Flow for Receive Endpoint 0
MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3
Freescale Semiconductor
Universal Serial Bus Module (USB)
Technical Data
159