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Bootstrap loader

ST10F276Z5

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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.

Figure 11.

CAN bootstrap loader sequence

BSL initialization time, > 1ms @ fCPU = 40 MHz.

Zero frame (CAN message: standard ID = 0, DLC = 0), sent by host.

CAN message (standard ID = E6h, DLC = 3, Data0 = D5h, Data1-Data2 = IDCHIP_low-high), sent by the ST10F276Z5 on

request.

128 bytes of code / data, sent by host.

Caution: CAN1_TxD is only driven a certain time after reception of the zero byte (1.3ms @ fCPU = 40 MHz).

Internal Boot ROM / Test-Flash.

Int. Boot ROM / Test-Flash BSL-routine

128bytes

user software

P0L.4

CAN1_TxD

CAN1_RxD

CSP:IP

RSTIN

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