L6472PD datasheet(55/69 Pages) STMICROELECTRONICS

55 / 69 page

L6472

Programming manual

Doc ID 022729 Rev 1

55/69

9.2.1

Command management

The host microcontroller can control motor motion and configure the L6472 through a

complete set of commands.

All commands are composed by a single byte. After the command byte, some argument

bytes should be needed (see Figure 22). Argument length can vary from 1 to 3 bytes.

Figure 22.

Command with 3-byte argument

By default the device returns an all zeroes response for any received byte, the only

exceptions are GetParam and GetStatus commands. When one of these commands is

received the following response bytes represents the related register value (see Figure 23).

Response length can vary from 1 to 3 bytes.

Figure 23.

Command with 3-byte response

During response transmission, new commands can be sent. If a command requiring a

response is sent before the previous response is completed, the response transmission is

aborted and the new response is loaded into the output communication buffer (see

Figure 24).

Figure 24.

Command response aborted

When a byte that does not correspond to a command is sent to the IC, it is ignored and the

WRONG_CMD flag in the STATUS register is raised (see Section 9.1.19).

9.2.2

Nop

Nothing is performed.

Table 34.

NOP command structure

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

From host

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