MC68HC908JW32_09 Datasheet, PDF (149/232 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

11.3.2 USB Control Logic
The USB control logic handle the following functions:
• For transmit data
– Packet creation
– CRC generation
– NRZI encoding
– Bit stuffing
• For receive data
– Sync detection
– Packet Identification
– End-of-packet (EOP) detection
– CRC validation
– NRZI decoding
– Bit unstuffing
• For error detection
– Bad CRC
– Timeout detection for EOP
– Bit stuffing violation
USB Module Architecture
11.3.3 USB Endpoint Configuration
A single configuration and 2 interfaces are supported by the module. Endpoint 0 is always used as control
endpoint. The interface number for endpoint 1 to 4 are programmable through USB interface control
register (UINTFCR). The endpoint type and direction of all endpoint 1 to 4 is software programmable to
either BULK or INTERRUPT and either IN or OUT respectively. The endpoint configuration is
summarized in Table 11-1
Table 11-1. Endpoint Summary
Endpoint
Number
0
1
2
3
4
Configuration
Number
—
1
1
1
1
Interface
Number
—
EP1INT
EP2INT
EP3INT
EP4INT
Direction
IN/OUT
IN/OUT
IN/OUT
IN/OUT
IN/OUT
Type
Control
Bulk/
Interrupt
Bulk/
Interrupt
Bulk/
Interrupt
Bulk/
Interrupt
MC68HC908JW32 Data Sheet, Rev. 6
Freescale Semiconductor
149