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© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
User manual Rev. 02 — 23 May 2005 4 of 133
Philips Semiconductors
UM10109
P89LPC932A1 User manual
1.1.4 Increased ISP/IAP functionality
1.1.4.1 Support for the watchdog timer
The ISP code has been modified to set the WDT prescaler (in WDCON) and WDL register
to their maximum values. Other WDCON bits are unchanged and the ISP code does not
explicitly enable or disable the WDT. Periodic feeds are provided within the ISP code to
support applications that entered the ISP code with an enabled WDT. This functionality
was not provided in the ISP code on the P89LPC932.
1.1.4.2 XDATA data buffer option added for programming code memory
The “program user code page” function on the P89LPC932 used IDATA as the 64 byte
data buffer. An option is provided to allow the user to specify that XDATA is to be used
instead as the buffer source. If the F1 flag (PSW.1) is set, then XDATA is used. If the F1
flag (PSW.1) is cleared, then IDATA is used.
1.1.4.3 Port 0 initialization
On the P89LPC932 the ISP code during initialization programmed all bits of Port 0 to the
quasi-bidirectional mode and set these port pins HIGH. This has been changed such that
only the TxD and RxD pins have their port mode programmed during ISP initialization. All
other Port 0 pins remain in their previous state (for example, input-only mode following a
reset).
1.1.4.4 Direct load of UART baud rate fix
A bug identified in the “direct load of baud rate” ISP function has been fixed. The baud rate
source for this function has been changed from Timer 1 to the BRG.
1.1.4.5 Boot Vector and IAP entry points modified
To protect against errant code execution incrementing into the ISP or IAP routines,
software reset instructions have been added to the beginning of these code blocks. This
required that the ISP and IAP entry points be changed. The ISP entry point has changed
to 1F00H resulting in a default Boot Vector of 1FH. The IAP entry point has changed to
FF03H.
1.1.4.6 IAP authorization key
IAP functions which write or erase code memory require an authorization key be set by
the calling routine prior to performing the IAP function call. This authorization key is set by
writing 96H to RAM location FFH. See Section 18.13 “
IAP authorization key” on page 118
After the function call is processed by the IAP routine, the authorization key will be
cleared. Thus it is necessary for the authorization key to be set prior to EACH call to
PGM_MTP that requires a key. If an IAP routine that requires an authorization key is
called without a valid authorization key present, the MCU will perform a reset.
1.1.4.7 Hardware write enable (WE) key
This device has hardware write enable protection. This protection applies to both ISP and
IAP modes and applies to both the user code memory space and the user configuration
bytes (UCFG1, BOOTVEC, and BOOTSTAT). This protection does not apply to
commercial programmer modes. When enabled, user code requesting a write function via
IAP or IAP-Lite will need to explicitly set a Write Enable flag prior to requesting the write
function. See Section 18.14 “
Flash write enable” on page 119