NXP Semiconductors P89LPC9321 UM10310, Руководство пользователя

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UM10310_1 © NXP B.V. 2008. All rights reserved.
User manual Rev. 01 — 1 December 2008 10 of 139
NXP Semiconductors
UM10310
P89LPC9321 User manual
1.5 Special function registers
Remark: SFR 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.