P89V51RD2 Datasheet, PDF (10/75 Pages) NXP Semiconductors – 8-bit 80C51 5 V low power 64 kB Flash microcontroller with 1 kB RAM

Philips Semiconductors
P89V51RD2
8-bit microcontrollers with 80C51 core
6. Special function registers
Remark: Special Function Registers (SFRs) accesses are restricted in the following
ways:
• User must not attempt to access any SFR locations not defined.
• Accesses to any defined SFR locations must be strictly for the functions for the
SFRs.
• SFR bits labeled ‘-’, ‘0’ or ‘1’ can only be written and read as follows:
– ‘-’ Unless otherwise specified, must be written with ‘0’, but can return any value
when read (even if it was written with ‘0’). It is a reserved bit and may be used in
future derivatives.
– ‘0’ must be written with ‘0’, and will return a ‘0’ when read.
– ‘1’ must be written with ‘1’, and will return a ‘1’ when read.
9397 750 12964
Product data
Rev. 01 — 01 March 2004
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
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