UM10310_1 © NXP B.V. 2008. All rights reserved.
User manual Rev. 01 — 1 December 2008 130 of 139
NXP Semiconductors UM10310
P89LPC9321 User manual
Table 122. Boot Status (BOOTSTAT) bit description
Bit Symbol Description
0 BSB Boot Status Bit. If programmed to logic1, the P89LPC9321 will always start execution at an address
comprised of 00H in the lower eight bits and BOOTVEC as the upper bits after a reset. (See Section 6.1
Reset vector).
1:4 - reserved
5 AWP Activate Write Protection bit. When this bit is cleared, the internal Write Enable flag is forced to the set
state, thus writes to the flash memory are always enabled. When this bit is set, the Write Enable internal
flag can be set or cleared using the Set Write Enable (SWE) or Clear Write Enable (CWE) commands.
6 CWP Configuration Write Protect bit. Protects inadvertent writes to the user programmable configuration
bytes (UCFG1, BOOTVEC, and BOOTSTAT). If programmed to a logic 1, the writes to these registers
are disabled. If programmed to a logic 0, writes to these registers are enabled.
This bit is set by programming the BOOTSTAT register. This bit is cleared by writing the Clear
Configuration Protection (CCP) command to FMCON followed by writing 96H to FMDATA.
7 DCCP Disable Clear Configuration Protection command. If Programmed to ‘1’, the Clear Configuration
Protection (CCP) command is disabled during ISP or IAP modes. This command can still be used in
ICP or parallel programmer modes. If programmed to ‘0’, the CCP command can be used in all
programming modes. This bit is set by programming the BOOTSTAT register. This bit is cleared by
writing the Clear Configuration Protection (CCP) command in either ICP or parallel programmer modes.