Equinox Systems GEMINI Podręcznik Użytkownika Pobierz pdf (Strona 34)

User Guide V1.10

Target Settings continued

Action Description

9 Programmer waits for period T3.

- This time allows the target system RESET to reach 0V.

During this period, the target microcontroller will start to execute code.

The target microcontroller will jump to the address pointed to by the ‘Boot

Vector’ and will then jump to the ‘Boot Loader’ code.

10 Programmer send the character ‘U’ to the target microcontroller to initiate ‘Serial

Programming Mode.

The programmer should now be able to communicate with the target

microcontroller ‘Boot Loader’ code.

11 The programmer sends the relevant command or series of commands to the

target microcontroller.

The target microcontroller should send back the required response(s) to the

ISP commands sent by the programmer.

12 The programmer asserts the PROG_RESET pin again.

13 Programmer waits for period T2

14 Programmer switches off the Vpp generator.

The voltage on the PROG_VPP starts to decay from +12V to +5V

15 Programmer waits for period T5.

This delay allows the Vpp voltage to decay from +12V to a stable +5V level.

16 The programmer performs the following actions:

Writes the value ‘00h’ into the ‘Status Byte’

Writes the value ‘0FCh’ into the ‘Boot Vector’

Tri-states the PROG_RESET pin.

17 Programmer waits for period T3.

- This time allows the target system RESET to reach 0V.

During this period, the target microcontroller will start to execute code.

The target microcontroller will jump to address 0000h and start execution of

the user firmware.

Figure 21 continued

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Equinox Systems GEMINI Podręcznik Użytkownika Strona 34