ST7LITE2 datasheet(129/131 Pages) STMICROELECTRONICS

129 / 131 page

ST7LITE2

129/131

16 IMPORTANT NOTES

16.1 EXECUTION OF BTJX INSTRUCTION

When testing the address $FF with the

"BTJT" or "BTJF" instructions, the CPU may

perform an incorrect operation when the rel-

ative jump is negative and performs an ad-

dress page change.

To avoid this issue, including when using a C

compiler, it is recommended to never use ad-

dress $00FF as a variable (using the linker

parameter for example).

16.2 ADC CONVERSION SPURIOUS RESULTS

Spurious conversions occur with a rate lower

than 50 per m illi on . S u ch con ve rs io ns

happen when the measured voltage is just

between 2 consecutive digital values.

Workaround

A software filter should be implemented to

remove erratic conversion results whenever

they may cause unwanted consequences.

16.3 A/ D CONVERTER ACCURACY FOR FIRST

CONVERSION

When the ADC is enabled after being pow-

ered down (for example when waking up

from HALT, ACTIVE-HALT or setting the

ADON bit in the ADCCSR register), the first

conversion (8-bit or 10-bit) accuracy does

not meet the accuracy specified in the da-

tasheet.

Workaround

In order to have the accuracy specified in the

datasheet, the first conversion after a ADC

switch-on has to be ignored.

ST7LITE2 Datasheet(PDF) 129 Page - STMicroelectronics