AT89C5131A-L Atmel Corporation, AT89C5131A-L Datasheet - Page 10

• Manufacturer Part Number: AT89C5131A-L
• Manufacturer: Atmel Corporation

Specifications of AT89C5131A-L

• Flash (kbytes): 32 Kbytes
• Max. Operating Frequency: 48 MHz
• Cpu: 8051-12C
• Max I/o Pins: 34
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Sram (kbytes): 1.25
• Eeprom (bytes): 1024
• Self Program Memory: API
• Operating Voltage (vcc): 3.0 to 3.6
• Timers: 4
• Isp: UART/USB
• Watchdog: Yes

Physical Layer
48 MHz Frequency
Auto-Configuration
10
AT89C5131A USB Bootloader
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 5. USB Bus Topography
The USB is used to transmit information that has the following configuration:
•
•
The bootloader includes a function which will automatically setup the PLL frequency (48MHz)
versus the different XTAL configuration used on the application.
The table below shows the allowed frequencies compatible with the USB bootloader
48 MHz auto-generation.
USB DFU using the Default Control Endpoint only (endpoint 0) with a 32 bytes length.
48 MHz for USB controller: USB clock configuration performed by the bootloader
X1 or X2
Modes
Clock
PC Driver
PC Application
6 MHz
OK
8 MHz
OK
PC (Host)
12 MHz
OK
16 MHz
OK
Downstream Transfer: OUT
Upstream Transfer: IN
USB Line
20 MHz
OK
24 MHz
OK
Application (Device)
32 MHz
OK
40 MHz
OK
Device driver/API
Firmware
4287E–USB–04/08
48 MHz
OK