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RC Calibration Ultra 09

brian4
Associate II
Posted on February 11, 2008 at 14:11

RC Calibration Ultra 09

2 REPLIES 2
brian4
Associate II
Posted on February 11, 2008 at 11:00

Hi

Just starting to use th ST7 Lite Ultra 09, the data sheet states that the calibration data is 10 bit and held in memory DEE0 (hi Byte) and DEE1 (lo byte)

The 2 bits of the lower byte shares the SICSR register in assembler how should I read the calibration and set the SICSR & RCCR.

Regards, Brian

schaeublinconsu
Associate II
Posted on February 11, 2008 at 14:11

Hi Brian

Use this:

;

; Clock

; 10 Bit RCCR to load

; Option Byte: CKSEL[1:0] = 00

;

.ini_st7

ld A, $DEE2 ; Calbration value (Special Bytes outside Flash)

ld RCCR, A ; set to 8 MHz @ 3.3 Volts @ 25°C CR[9:0]

ld A, $DEE3 ;

and A, #%01100000

ld SICSR, A ; CR[1:0]

More precise information You can find in the FOXU... data sheet:

1. The DEE0h and DEE1h addresses are located in a reserved area in non-volatile memory. They are readonly

bytes for the application code. This area cannot be erased or programmed by any ICC operations.

For compatibility reasons with the RCCRL register, CR[1:0] bits are stored in the 5th and 6th position of

DEE1 address.

Kind regards

hansjusch