2

T89C51RB2/RC2/IC2 Bootloader Errata Sheet

4187A–8051–10/02

5.

Bad Interrupt Handling During an API Call

Interrupts are not disabled during all API process. This may cause interaction with software application interrupts using

MOVX instruction.

API functions always enable interrupts (set EA) before exiting. This may cause trouble if API is called from a software

program section requiring interrupts to be disabled.

Workaround

The software application should save and disable EA before an API call. On API return, the software application should

restore EA setting.

6.

Program Data Byte and Data Page API Return Value

The PROGRAM DATA BYTE API and DATA PAGE API returns “01h” instead of “00” into the accumulator, when Flash

write process passed.

Workaround

The software application should take into account that return value is “01” with 1.1.1 bootloader version.

7.

No Further ISP is Possible When OSCB Fuse Bit Set and 32 kHz are Connected to XTAL2 for T89C51IC2

Product Only

When OSCB fuse bit is set (written with 0), and XTAL2A/B pins connected to a 32 kHz oscillator, no serial ISP is

possible.

Workaround

Connect at least a 1.8432 MHz signal to XTAL2A pin.