P89V51RD2FN NXP Semiconductors, P89V51RD2FN Datasheet - Page 19

• Manufacturer Part Number: P89V51RD2FN
• Description: MCU 8-Bit 89V 80C51 CISC 64KB Flash 5V 40-Pin PDIP Tube
• Manufacturer: NXP Semiconductors

Specifications of P89V51RD2FN

• Package: 40PDIP
• Device Core: 80C51
• Family Name: 89V
• Maximum Speed: 40 MHz
• Ram Size: 1 KB
• Program Memory Size: 64 KB
• Operating Supply Voltage: 5 V
• Data Bus Width: 8 Bit
• Program Memory Type: Flash
• Number Of Programmable I/os: 32
• Interface Type: SPI/UART
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 3

NXP Semiconductors
P89V51RB2_RC2_RD2_5
Product data sheet
6.2.8 Dual data pointers
The device has two 16-bit data pointers. The DPTR Select (DPS) bit in AUXR1
determines which of the two data pointers is accessed. When DPS = 0, DPTR0 is
selected; when DPS = 1, DPTR1 is selected. Quickly switching between the two data
pointers can be accomplished by a single INC instruction on AUXR1 (see
Fig 6. Internal and external data memory structure
2FFH
000H
2FFH
000H
EXPANDED RAM
ADDRESSING)
EXPANDED
(INDIRECT
768 B
Rev. 05 — 12 November 2009
RAM
FFFFH
0300H
FFH
7FH
80H
00H
INTERNAL RAM
INTERNAL RAM
(INDIRECT AND
ADDRESSING)
ADDRESSING)
ADDRESSING)
LOWER 128 B
UPPER 128 B
EXTRAM = 0
EXTERNAL
P89V51RB2/RC2/RD2
(INDIRECT
(INDIRECT
MEMORY
DIRECT
DATA
8-bit microcontrollers with 80C51 core
FFFFH
0000H
FFH
80H
REGISTERS (SFRs)
ADDRESSING)
ADDRESSING)
EXTERNAL
FUNCTION
(INDIRECT
EXTRAM = 1
MEMORY
SPECIAL
(DIRECT
DATA
© NXP B.V. 2009. All rights reserved.
Figure
002aaa517
7).
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