AN2294 Freescale Semiconductor / Motorola, AN2294 Datasheet - Page 9

• Manufacturer Part Number: AN2294
• Description: MC68SZ328 USB Configuration Setup Application Note
• Manufacturer: Freescale Semiconductor / Motorola

3.2 Programming the USB Device Core (UDC)
The USB Device Core implements most of the USB protocol in hardware. As shown in Figure 7, the UDC
is the front-end device for communication with the USB transceiver and the peripheral bus.
The following steps are found in the MC68SZ328 Reference’s Manual on programming the UDC registers
but are explained in greater detail in this application note.
UDC Register Programming Instructions
MOTOROLA
1. Perform a hard reset or a software rest (RST bit in USB_ENAB register).
Software option—USB_ENAB = 0x8000 0000
This sets the RST bit and the ENAB bits. Wait for the bit to clear before continuing to program
registers. Check that the CFG bit in the CFGSTAT register is set.
Write Port
Dual Port,
4 banks
Figure 7. USB Device Core (UDC) Block Diagram
x 9 bits
Muxing
FIFO
RAM
FIFO
RAM
Freescale Semiconductor, Inc.
USB DMA
For More Information On This Product,
Control
Read Port
MC68SZ328 Application Note
To/From USB Transceiver
Internal Peripheral Bus
Go to: www.freescale.com
UDC Core
128 bytes
128 bytes
32 bytes
16 bytes
16 bytes
Control
... x5...
Control
FIFO0
FIFO1
FIFO2
FIFO3
FIFO4
Peripheral Bus
FIFO
FIFO
(BlueLine)
Bus IP
Register Decodes
FIFO
Interrupts
USB Configuration/Control
Endpoint Configuration
Module Specification Revision
Frame Count/Match
Endpoint Buffer Download
Synchronization
Control Logic
Configuration
USB Core
Synchronization
& Transaction
Application
Decode
Software Interface
Decode
Bus
9