AT89C5115 Atmel Corporation, AT89C5115 Datasheet - Page 6

• Manufacturer Part Number: AT89C5115
• Manufacturer: Atmel Corporation

Specifications of AT89C5115

• Flash (kbytes): 16 Kbytes
• Max. Operating Frequency: 40 MHz
• Cpu: 8051-12C
• Max I/o Pins: 20
• Uart: 1
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 62.5
• Sram (kbytes): 0.5
• Eeprom (bytes): 2048
• Self Program Memory: API
• Operating Voltage (vcc): 3.0 to 5.5
• Timers: 4
• Isp: UART
• Watchdog: Yes

In-System
Programming
Boot Process
Hardware Condition
6
T89C5115 UART Bootloader
The ISP allows the user to program or reprogram a microcontroller’s on-chip Flash memory
through the serial line without removing it from the system and without the need of a pre-pro-
grammed application.
This section describes how to start the UART bootloader and all higher level protocol over the
serial line.
The bootloader can be activated in two ways:
•
•
The Hardware Condition forces the bootloader execution from reset.
The default factory Hardware Condition is assigned to port P1.
•
In order to offer the best flexibility, the user can define its own Hardware Condition on one of the
following Ports:
•
•
•
The Hardware Condition configuration is stored in three bytes called P1_CF, P3_CF, P4_CF.
These bytes can be modified by the user through a set of API or through an ISP command.
There is a priority between P1_CF, P3_CF and P4_CF (see boot process diagram).
Note:
Hardware condition
Regular boot process
P1 must be equal to FEh
Port1
Port3
Port4 (only bit0 and bit1)
The BLJB must ba at 0 (programmed) to be able to restart the bootloader.
If the BLJB is equal to 1 (unprogrammed) only the hardware parallel programmer can change this
bit (see T89C5115 Datasheet for more detail).
4225C–8051–03/08