ST10F280_12 datasheet(51/239 Pages) STMICROELECTRONICS

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ST10F280

Internal Flash memory

Doc ID 8673 Rev. 3

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smaller Baud rate pre-scaler factors and the implied higher quantization error

(see Figure 8).

The minimum Baud rate (BLow in the Figure 8) is determined by the maximum count

capacity of timer T6, when measuring the zero Byte, and it depends on the CPU clock.

Using the maximum T6 count 216 in the formula the minimum Baud rate can be calculated.

The lowest standard Baud rate in this case would be 1200 Baud. Baud rates below BLow

would cause T6 to overflow. In this case ASC0 cannot be initialized properly.

The maximum Baud rate (BHigh in the Figure 8) is the highest Baud rate where the

deviation still does not exceed the limit, so all Baud rates between BLow and BHigh are below

the deviation limit. The maximum standard Baud rate that fulfills this requirement is 19200

Baud.

Higher Baud rates, however, may be used as long as the actual deviation does not exceed

the limit. A certain Baud rate (marked ’I’ in Figure 8) may violate the deviation limit, while an

even higher Baud rate (marked ’II’ in Figure 8) stays very well below it. This depends on the

host interface.

Figure 8.

Baud rate deviation between host and ST10F280

ST10F280 Datasheet(PDF) 51 Page - STMicroelectronics