AT89C51SND1_06 ATMEL [ATMEL Corporation], AT89C51SND1_06 Datasheet - Page 9

• Manufacturer Part Number: AT89C51SND1_06
• Description: USB Microcontrollers
• Manufacturer: ATMEL [ATMEL Corporation]

Physical Layer
4254C–MP3–03/06
Note:
Table 6. SBV Byte – Software Boot Vector
Reset Value = XXXX XXXX, UUUU UUUU after an hardware full chip erase.
Table 7. SSB Byte – Software Security Byte
Reset Value = XXXX XXXX, UUUU UUUU after an hardware full chip erase.
The USB norm specifies all the transfers over the USB line. The USB specification also includes
several CLASS and SUB-CLASS specifications. These stand-alone documents are used by the
manufacturer to implement a USB link between a PC and a device supporting the In-System
Programming. Mostly, the USB specification is implemented by hardware (automatic reply,
handshakes, timings, …) and the USB Classes and SubClasses are implemented by software at
a data level.
Figure 3. USB Bus Topography
The USB used to transmit information has the following configuration:
•
•
Bit Number
Bit Number
ADD15
SSB7
USB DFU using the Default Control Endpoint only (endpoint 0) with a 32 bytes length.
48 MHz for USB controller: frequency auto-detection performed by the bootloader.
7-0
7-0
7
7
1. X2B initializes the X2 bit in CKCON during the reset phase.
2. In order to ensure boot loader activation at first power-up, AT89C51SND1 products are deliv-
3. Bits 0 to 3 (LSN) can only be programmed by hardware mode.
PC Driver
PC Application
ered with BLJB programmed.
Mnemonic
Mnemonic
ADD15:8
SSB7:0
ADD14
SSB6
Bit
Bit
6
6
Description
MSB of the user’s boot loader 16-bit address location
Refer to the boot loader datasheet for usage information (boot loader dependent)
Description
Software Security Byte Data
Refer to the boot loader datasheet for usage information (boot loader dependent)
PC (Host)
ADD13
SSB5
5
5
ADD12
SSB4
Downstream Transfer: OUT
Upstream Transfer: IN
4
4
USB line
ADD11
SSB3
3
3
Application (Device)
ADD10
SSB2
2
2
AT89C51SND1
ADD9
SSB1
Device driver/API
Firmware
1
1
ADD8
SSB0
0
0
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