DS89C430-DS89C450 Dallas Semiconducotr, DS89C430-DS89C450 Datasheet - Page 14

• Manufacturer Part Number: DS89C430-DS89C450
• Description: Ultra-High-Speed Flash Microcontrollers
• Manufacturer: Dallas Semiconducotr

Figure 5. Functional Diagram
DETAILED DESCRIPTION
The DS89C430, DS89C440, 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, DS89C440 = 32kB, 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/DS89C440/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
DS89C430/DS89C440/
WATCHDOG TIMER
POWER MANAGER
SEQUENCER
DECODER
CONTROL
DS89C450
AND
IR
AND
INTERNAL CONTROL BUS
SERIAL I/O
REGISTERS
INTERNAL
COUNTERS
CLOCK
RESET
AND
TIMER/
14 of 47
INTERRUPT
CPU
1kB x 8
RAM
CONTROL
MEMORY
16kB/32kB
64kB x 8
LOADER
DPTR1
DPTR
SFRs
FLASH
SP
ROM
P0 P1 P2 P3
AR INC
I/O PORTS
ADDRESS BUS
AR
PC