AT89C5131A(2004) View Datasheet(PDF) - Atmel Corporation
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Description
Manufacturer
AT89C5131A Datasheet PDF : 33 Pages
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AT89C5131A USB Bootloader
Protocol
Device Firmware Upgrade
Introduction
DFU Specific Requests
Device Firmware Upgrade is the mechanism for accomplishing the task of upgrading the
device firmware. Any class of USB device can exploit this capability by supporting the
requirements specified in this document.
Because it is impractical for a device to concurrently perform both DFU operations and
its normal run-time activities, those normal activities must cease for the duration of the
DFU operations. Doing so means that the device must change its operating mode; i.e., a
printer is not a printer while it is undergoing a firmware upgrade; it is a PROM program-
mer. However, a device that supports DFU is not capable of changing its mode of
operation on its own. External (human or host operating system) intervention is
required.
In addition of the USB standard requests, 7 DFU class-specific requests are employed
to accomplish the upgrade operations (Table 1):
Table 1. DFU Class-specific Requests
bmRequestType
bRequest
0010 0001b
DFU_DETACH (0)
0010 0001b
DFU_DNLOAD (1)
1010 0001b
DFU_UPLOAD (2)
1010 0001b
DFU_GETSTATUS (3)
0010 0001b
DFU_CLRSTATUS (4)
1010 0001b
DFU_GETSTATE (5)
0010 0001b
DFU_ABORT (6)
wValue
wTimeout
wBlock
wBlock
Zero
Zero
Zero
Zero
wIndex
Interface (4)
Interface (4)
Interface (4)
Interface (4)
Interface (4)
Interface (4)
Interface (4)
wLength
Zero
Length
Length
6
Zero
1
Zero
Data
none
Firmware
Firmware
Status
none
State
none
DFU Descriptors Set
DFU Device Descriptor
The device exports the DFU descriptor set, which contains:
• A DFU device descriptor
• A single configuration descriptor
• A single interface descriptor (including descriptors for alternate settings, if present)
• A single functional descriptor
This descriptor is only present in the DFU mode descriptor set. The DFU class code is
reported in the bDeviceClass field of this descriptor.
Table 2. USB Parameters
Parameter
Vendor ID
Product ID
Release Number
Atmel – AT89C5131A Bootloader
0x03EB
0x2FFD
0x0000
11
4287C–USB–11/04
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