ST10F276E datasheet(58/235 Pages) STMICROELECTRONICS

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Bootstrap loader

ST10F276E

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Doc ID 12303 Rev 3

Figure 10.

Baud rate deviation between host and ST10F276E

The minimum baud rate (BLow in Figure 10) is determined by the maximum count capacity

of timer T6, when measuring the zero byte, that is, it depends on the CPU clock. Using the

maximum T6 count 216 in the formula the minimum baud rate is 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 Figure 10) is the highest baud rate where the deviation

still does not exceed the limit, that is, 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 10) may, for example, violate the deviation

limit, while an even higher baud rate (marked “II” in Figure 10) stays well below it. This

depends on the host interface.

5.4

Standard bootstrap with CAN

5.4.1

Features

The bootstrap via CAN has the same overall behavior as the bootstrap via UART:

●

Same bootstrapping steps;

●

Same bootstrap method: Analyze the timing of a predefined frame, send back an

acknowledge frame BUT only on request, load a fixed number of bytes and run;

●

Same functionalities: Boot with different crystals and PLL ratios.

ST10F276E 데이터시트(PDF) 58 Page - STMicroelectronics