User Configuration Bytes - Philips P89LPC938 User Manual

Philips Semiconductors
Table 114: IAP function calls
IAP function
Read Sector CRC
Read Global CRC
Read User Code

19.17 User configuration bytes

A number of user-configurable features of the P89LPC938 must be defined at power-up
and therefore cannot be set by the program after start of execution. These features are
configured through the use of an Flash byte UCFG1 shown in
Table 115: Flash User Configuration Byte (UCFG1) bit allocation
Bit 7
Symbol WDTE
Unprogrammed 0
value
Table 116: Flash User Configuration Byte (UCFG1) bit description
Bit Symbol Description
0 FOSC0 CPU oscillator type select. See
shown in Table 117
1 FOSC1
2 FOSC2
3 - reserved
User manual
...continued
6 5 4
RPE BOE WDSE
1 1 0
Section 2 "Clocks"
are reserved for future use should not be used.
Rev. 03 — 7 June 2005
IAP call parameters
Input parameters:
ACC = 05h
R7= sector address
Return parameter(s):
R4= CRC bits 31:24
R5= CRC bits 23:16
R6= CRC bits 15:8
R7= CRC bits 7:0 (if no error)
R7= error status (if error)
Carry= set on error, clear on no error
Input parameters:
ACC = 06h
Return parameter(s):
R4= CRC bits 31:24
R5= CRC bits 23:16
R6= CRC bits 15:8
R7= CRC bits 7:0 (if no error)
R7= error status (if error)
Carry= set on error, clear on no error
Input parameters:
ACC = 07h
R4= address (MSB)
R5= address (LSB)
Return parameter(s):
R7= data
3 2
- FOSC2
0 0
for additional information. Combinations other than those
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
UM10119
P89LPC938 User manual
Table 116
1 0
FOSC1 FOSC0
1 1
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