DocID024501 Rev 2

9/16

AN4290

SPI communication interface

16

During the response transmission the device is still operative and can receive and execute

new commands (see Figure 5). If a command, requiring a new response, is received before

the end of the transmission of the current response, the new response replaces the previous

one (see Figure 6).

Figure 5. Response transmission management

Figure 6. Response aborting

In case of registers, which can autonomously change their value such as the ABS_POS

register, the response corresponds to the value of the register after the GetParam command

has been received and decoded. If the register value changes later, the response is not

updated accordingly.

CONFIG

2

Writable when in HiZ only

STATUS

2

Read only

1. L6470 and L6480 only.

2. L6472, L6474 and L6482 only.

3. L6480 and L6482 only.

Table 4. Number of arguments or response bytes of the SetParam \ GetParam

commands according to the target register (continued)

Register

Number of bytes

Notes

ABS_POS

(byte 2)

ABS_POS

(byte 1)

ABS_POS

(byte 0)

GetParam(ABS_POS)

Unknown

NOP

NOP

From MCU (MOSI)

To MCU (MISO)

SoftStop

The command is executed

AM16749v1

GetParam(OCD_TH)

GetParam(STEP_MODE)

OCD_TH

(byte 0)

ACC

(byte 1)

STEP_MODE

(byte 0)

GetParam(ACC)

Unknown

Don’t care

From MCU (MOSI)

To MCU (MISO)

The new response

interrups and repleaces

the previous one

AM16750v1