AN2294 Freescale Semiconductor / Motorola, AN2294 Datasheet - Page 12

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

Software Interface
Table 5 shows the register configuration for endpoints 0 through 4 in Code Example 2 on page 11.
The selection of the current EndPoint information from all the EndPtBuf registers is based on the current
configuration and current alternate setting of the interface with which the EndPtBuf is associated.
EndPtBuf0 (EndPtBuf information for End Point 0) is always fixed for EndPoint 0.
12
[31:29]
[28:27]
[26]
[25:16]
[15:14]
[13:3]
[2:0]
Endpt0
Endpt1
Endpt2
Endpoint
Endpt3
Endpt4
Bit Field
(EP#)
Configuration
AltSetting
Type
Dir
MaxPktSize
TRXTYP
Reserved
FifoNum
Type
00
01
01
01
01
Table 4. EndPBufs Register Description Table (Continued)
Freescale Semiconductor, Inc.
Interface
Type of endpoint:
00 = Control
01 = Reserved
10 = Bulk
11 = Interrupt
Direction of the Endpoint:
0 = OUT endpoint
1 = IN endpoint
Maximum packet size for endpoint:
0x08 = 8 bytes
0x10 = 16 bytes
0x20 = 32 bytes
0x40 = 64 bytes
FIFO Number—This field maps the endpoint to one of the USB Device module’s
hardware FIFOs. Multiple UDC endpoints may map to a single hardware FIFO. It is
up to the software to monitor and control any data hazards related to operation in
this way.
The hardware FIFOs that are available are:
Alternate setting number—Maximum up to 4 alternate settings.
These bits must be set to 2’b00 for endpoint 0 and 2’b11 for all other endpoints.
For More Information On This Product,
FIFO 0 (32 bytes)
FIFO 1 (16 bytes)
FIFO 2 (16 bytes)
FIFO 3 (128 bytes)
FIFO 4 (128 bytes)
00
00
00
00
00
MC68SZ328 Application Note
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Alternate Setting
000
000
000
000
000
Table 5.
Control
Type
Bulk
Bulk
Bulk
Bulk
Description
Direction
In/Out
Out
Out
In
In
Packet Size
Maximum
16 bytes
16 bytes
64 bytes
64 bytes
8 bytes
MOTOROLA
Number
FIFO
0
1
2
3
4