UM10310_1 © NXP B.V. 2008. All rights reserved.
User manual Rev. 01 — 1 December 2008 127 of 139
NXP Semiconductors UM10310
P89LPC9321 User manual
18.17 User configuration bytes

A number of user-configurable features of the P89LPC9321 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 and UCFG2 shown in Table112 and

Table115.

Read Sector CRC 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
Read Global CRC 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
Read User Code Input parameters:
ACC = 07h
R4= address (MSB)
R5= address (LSB)
Return parameter(s):
R7= data
Table 110. IAP function calls …continued
IAP function IAP call parameters
Table 111. Flash User Configuration Byte 1 (UCFG1) bit allocation
Bit 76543210
Symbol WDTE RPE BOE1 WDSE BOE0 FOSC2 FOSC1 FOSC0
Unprogrammed
value 01100011
Table 112. Flash User Configuration Byte 1 (UCFG1) bit description
Bit Symbol Description
0 FOSC0 CPU oscillator type select. See Section 2 “Clocks for additional information. Combinations other th an those
shown in Tabl e 113 are reserved for future use should not be used.
1FOSC1
2FOSC2
3 BOE0 Brownout Detect Configuration (see Section 5.1 “Bro wnout detection)