DS89C420-ENG Maxim Integrated Products, DS89C420-ENG Datasheet - Page 30

• Manufacturer Part Number: DS89C420-ENG
• Description: IC MCU ULTRA 25MHZ HP 44-TQFP
• Manufacturer: Maxim Integrated Products
• Series: 89Cr

Specifications of DS89C420-ENG

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: EBI/EMI, SIO, UART/USART
• Peripherals: Power-Fail Reset, WDT
• Number Of I /o: 32
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -

Figure 11. Page Mode 1, External Memory Cycle (CD1:CD0 = 10)
Internal Memory Cycles
RD / WR
XTAL1
RD / WR
RD / WR
PSEN
Port 0
Port 2
ALE
PSEN
Port 0
Port 2
PSEN
Port 0
Port 2
ALE
ALE
MSB
Page Miss
MSBAdd
LSB
Page Miss
Inst
MSBAdd
LSB
Inst
Page Hit
LSB Add
LSB
MOVX
External Memory Cycles
Page Miss
MOVX
LSB
MOVX executed
MOVX
Page Hit
30 of 47
LSB Add
MSB
Data Access
Inst
MOVX executed
LSB Add
LSB
Data
MSBAdd
Inst
MSB
Page Miss
Data Access
MOVX executed
LSB
Inst
LSB Add
Data Access
MSB
Data
Data Access
LSB Add
LSB
next instruction
Data
MSBAdd
Page Miss
Data
MSB
PAGES=00
PAGES=01
PAGES=10