Manual

AT89C5132

4256A–USB–06/03

Note: 1. Alternate settings can be used by an application to access additional memory seg-

ments. In this case, it is suggested that each alternate setting employs a string

descriptor to indicate the target memory segment; e.g., “EEPROM”. Details concern-

ing other possible uses of alternate settings are beyond the scope of this document.

However, their use is intentionally not restricted because it is anticipated that imple-

menters will devise additional creative uses for alternate settings.

DFU Functional Descriptor

Command Description This protocol allows to:

• Initiate the communication

• Program the Flash Data

• Read the Flash Data

• Program Configuration Information

• Read Configuration and Manufacturer Information

• Erase the Flash

• Start the application

Overview of the protocol is detailed in Appendix-A.

Table 8. DFU Functional Descriptor

Offset Field Size Value Description

0 bLength 1 07h Size of this descriptor, in bytes

1 bDescriptorType 1 21h DFU FUNCTIONAL descriptor type

2 bmAttributes 1 Bit mask

DFU Attributes:

bit 7..3 : reserved

bit 2: device is able to communicate via USB after Manifestation phase

1 = yes, 0 = no, must see bus reset

bit 1: bitCanUpload : upload capable 1 = yes, 0 = no

bit 0: bitCanDnload : download capable 1 = yes, 0 = no

3 wDetachTimeOut 2 Number

Time in milliseconds that the device will wait after receipt of the

DFU_DETACH request.

If this time elapses without a USB reset, the device will terminate the

Reconfiguration phase and revert back to normal operation. This

represents the maximum time that the device can wait (depending on its

timers, ...). The Host may specify a shorter timeout in the DFU_DETACH

request.

5 wTransferSize 2 Number

Maximum number of bytes that the device can accept per control-write

transaction