Philips 8-bit microcontroller with two-clock 80C51 core UM10109 Benutzerhandbuch

 

© Koninklijke Philips Electronics N.V. 2005. All rights reserved.

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.

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.

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).

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.

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.

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 

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.

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