P89V51RB2FA NXP Semiconductors, P89V51RB2FA Datasheet - Page 19

• Manufacturer Part Number: P89V51RB2FA
• Description: MCU 8BIT 80C51 16K FLASH, PLCC44
• Manufacturer: NXP Semiconductors

Specifications of P89V51RB2FA

• Controller Family/series: (8051) 8052
• Core Size: 8bit
• No. Of I/o's: 32
• Program Memory Size: 16KB
• Ram Memory Size: 1KB
• Cpu Speed: 40MHz
• Oscillator Type: External Only
• No. Of Timers: 4
• No. Of Pwm: RoHS Compliant

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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