DS89C430 Maxim, DS89C430 Datasheet - Page 14

• Manufacturer Part Number: DS89C430
• Description: The DS89C430 and DS89C450 offer the highest performance available in 8051-compatible microcontrollers
• Manufacturer: Maxim

Figure 5. Functional Diagram
DETAILED DESCRIPTION
The DS89C430 and DS89C450 are pin compatible with all three packages of the standard 8051 and include
standard resources such as three timer/counters, serial port, and four 8-bit I/O ports. The three part numbers vary
only by the amount of internal flash memory (DS89C430 = 16kB, DS89C450 = 64kB), which can be in-system/in-
application programmed from a serial port using ROM-resident or user-defined loader software. For volume
deployments, the flash can also be loaded externally using standard commercially available parallel programmers.
Besides greater speed, the DS89C430/DS89C450 include 1kB of data RAM, a second full hardware serial port,
seven additional interrupts, two extra levels of interrupt priority, programmable watchdog timer, brownout monitor,
and power-fail reset. Dual data pointers (DPTRs) are included to speed up block data-memory moves with further
enhancements coming from selectable automatic increment/decrement and toggle select operation. The speed of
MOVX data memory access can be adjusted by adding stretch values up to 10 machine cycles for flexibility in
selecting external memory and peripherals.
A power management mode consumes significantly lower power by slowing the CPU execution rate from one clock
period per cycle to 1024 clock periods per cycle. A selectable switchback feature can automatically cancel this
mode to enable normal speed responses to interrupts.
For EMI-sensitive applications, the microcontroller can disable the ALE signal when the processor is not accessing
external memory.
Dallas Semiconductor
WATCHDOG TIMER
SEQUENCER
POWER MANAGER
DECODER
CONTROL
DS89C430/
DS89C450
AND
IR
AND
INTERNAL CONTROL BUS
SERIAL I/O
REGISTERS
INTERNAL
COUNTERS
CLOCK
RESET
AND
TIMER/
DS89C430/DS89C450 Ultra-High-Speed Flash Microcontrollers
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INTERRUPT
CPU
1kB x 8
RAM
CONTROL
MEMORY
16kB/32kB
LOADER
64kB x 8
DPTR1
DPTR
SFRs
FLASH
SP
ROM
P0 P1 P2 P3
AR INC
I/O PORTS
ADDRESS BUS
AR
PC