ST L6470H, Manual

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L6470 Programming manual
Doc ID 16737 Rev 2 53/64
9.2.1 Command management
The host microcontroller can control motor motion and configure the L6470 through a
complete set of commands.
All commands are composed by a single byte. After the command byte, some bytes of
arguments should be needed (see
Figure 18 ). Argument length can vary from 1 to 3 bytes.
Figure 18. Command with three 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 19 ).
Response length can vary from 1 to 3 bytes.
Figure 19. Command with three byte responset
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 output communication buffer (see
Figure 20 ).
Figure 20. 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 STATUS register is raised (see paragraph 9.1.22).
9.2.2 Nop
Nothing is performed.
3$)
3$/
#OMMANDBYTE
!RGUMENTBYTE
-3"
!RGUMENTBYTE
,3"
!RGUMENTBYTE
X X X X
FROMHOST
TOHOST
3$)
3$/
#OMMANDBYTE
2ESPONSEBYTE
-3"
2ESPONSEBYTE
,3"
2ESPONSEBYTE X
./0 ./0 ./0
FROMHOST
TOHOST
3$)
3$/
#OMMAND
BYTERESPEXPECTED
#OMMAND
BYTERESPEXPECTED
2ESPONSEBYTE
-3"
2ESPONSEBYTE
-3"
2ESPONSEBYTE X
#OMMAND
NORESPEXPECTED
2ESPONSEBYTE
,3"
FROMHOST
TOHOST
#OMMAND
NORESPEXPECTED
#OMMAND
NORESPEXPECTED
#OMMANDRESPONSE
ISABORTED
Table 37. Nop command structure
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0 0 0 0 0 0 0 0 From host