MEMORY ORGANIZATION
PROGRAM MEMORY: Up to 8 Kbytes of the program memory can reside in the 87C51FA On-Chip EPROM. Up to 16 Kbytes of the program memory can reside in the 87C51FB on-chip EPROM. Up to 32 Kbytes of the program memory can reside in the 87C51FC on-chip EPROM. In addition the device can address up to 64K of program memory external to the chip.
DATA MEMORY: This microcontroller has a 256 x 8 on-chip RAM. In addition it can address up to 64 Kbytes of external data memory.

■ FX Core Architecture Device
■ Extended Automotive Temperature
   Range (b40§C to a125§C Ambient)
■ Available in 12 MHz, 16 MHz and
   20 MHz Versions
■ High Performance CHMOS EPROM
■ Three 16-Bit Timer/Counters
   — Timer 2 (Up/Down Counter)
■ Programmable Counter Array with:
   — High Speed Output,
   — Compare/Capture,
   — Pulse Width Modulator,
   — Watchdog Timer Capabilities
■ One-to-Three Level Program Lock
   System on EPROM
■ 8K On-Chip User Programmable
   EPROM in 87C51FA
■ 16K On-Chip User Programmable
   EPROM in 87C51FB
■ 32K On-Chip User Programmable
   EPROM in 87C51FC
■ 256 Bytes of On-Chip Data RAM
■ Quick Pulse Programming Algorithm
■ Boolean Processor
■ 32 Programmable I/O Lines
■ 7 Interrupt Sources
■ Four Level Interrupt Priority
■ Programmable Serial Channel with:
   — Framing Error Detection
   — Automatic Address Recognition
■ TTL and CMOS Compatible Logic
   Levels
■ 64K External Program Memory Space
■ 64K External Data Memory Space
■ MCSÉ-51 Fully Compatible Instruction
   Set
■ Power Saving Idle and Power Down
   Modes
■ ONCE (On-Circuit Emulation) Mode
■ RFI Reduction Mode
■ Available in PLCC and PDIP Packages