L9678P datasheet(113/203 Pages) STMICROELECTRONICS

113 / 203 page

DocID029274 Rev 3

113/203

L9678P, L9678P-S

Deployment drivers

202

6.1.3

Deployment control flow

Deployment control logic requires the following conditions to be true to successfully operate

a deployment:



POR = 1



SSM to be either in Safing State or Arming State



a valid arming condition processed by safing logic or FENH and FENL signals to be set

(depending on selection of internal or external safing engine)



"channel-specific deploy command request bits to be set via SPI in the Deploy

command Register (DEPCOM)



a global deployment state has to be active, as described in the following figure.

Figure 24. Global SPI deployment enable state diagram

In case a multiple deployment request would be needed, i.e. deploying the same channel in

sequence, a toggle on DEP_DISABLED has to be performed and a new DEPCOM

command on the same channel has to be sent.

The SPI DEPCOM command is ignored if the device is in the DEP_DISABLED state and the

deploy command is not set. While in DEP_ENABLED state, the following functionalities that

could be active are forced to their reset state:



All squib and DC sensor diagnostic current or voltage sources



All squib, DC sensor and ADC diagnostic mux settings, state machine, etc.

The SPI_LOCK and SPI_UNLOCK signals are available in the SPIDEPEN command:

High-side and Low-side enablers by internal/external safing are global and apply to all

channels. The Deploy commands in the Deploy Command Register (DEPCOM) are channel

specific.

Deployment requires a valid arming command from safing logic or the FENH and FENL

signals to be set any time before, during or after the specific sequence of deploy commands

is received. It is feasible for a deploy command to be received without a valid arming

command from safing logic or the FENH and FENL being set. In this case, the deploy

command will be terminated according to the Deploy Command Expiration Timer described

in Section 6.1.2. Likewise, a valid arming command or the FENH and FENL signals can be

set without receiving a Deploy Command. In this case, the enabling signals will remain

active according to the Arming Enable Pulse Stretch Timer or the FENx enabling state. The

Arming Enable Pulse Stretch Timers is available in the AEPSTS register.

L9678P 数据表(PDF) 113 Page - STMicroelectronics

L9678P 数据表(HTML) 113 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表下载