L9680 datasheet(217/277 Pages) STMICROELECTRONICS

217 / 277 page

DocID029257 Rev 1

217/277

L9680

System voltage diagnostics

276

DIAGCTRL_B (ADDRESS HEX 3B)

DIAGCTRL_C (ADDRESS HEX 3C)

DIAGCTRL_D (ADDRESS HEX 3D)

ADCREQ[A-D] bit fields, used to address the different measurements offered, are listed in

Table 18 for reference.

L9680 diagnostics is structured to take four automatic conversions at a time. In order to get

four measurements, four different SPI commands have to be sent (DIAGCTRL_A,

DIAGCTRL_B, DIAGCTRL_C and DIAGCTRL_D), in no particular order.

In case the voltage to be measured is not immediately available, the desired inputs for

conversion have to be programmed by SPI in advance, to allow them to attain a stable

voltage value. This case applies to the squib resistance measurement and diagnostics (refer

to Loop diagnostics control and results registers) and to the DC sensor measurement (refer

to Section 11).

CONVRDY_0 bit in GSW is equal to (NEWDATA_A or NEWDATA_B), while CONVRDY_1

bit in GSW corresponds to (NEWDATA_C or NEWDATA_D).

Each NEWDATAx flag is asserted when conversion is finished and cleared when result is

read out. However result is cleared only when new result for that register is available.

When a new request is received it is queued if other conversions are ongoing. The

conversions are executed in the same order as their request arrived. The queue is 4

measures long so it's possible to send all 4 requests at the same time and then wait for the

results. If a DIAGCTLRx command is received twice, the second conversion request will

overwrite the previous one.

Requests are sent to the L9680 IC via the ADC measurement Registers (ADCREQx) as

shown in Table 18. All diagnostics results are available on the ADCRESx registers, when

addressed by the related ADCREQx register (e.g. data requested by ADCREQA would be

written to ADCRESA).

18 17 16 15 14 13 12 11 10 9 8 7

6543210

MOSI

xxxxxx

x x x

ADCREQ_B [6:0]

MISO NEWDATA_B

ADCREQ_B [6:0]

ADCRES_B [9:0]

18 17 16 15 14 13 12 11 10 9 8 7

MOSI

x x x

ADCREQ_C [6:0]

MISO NEWDATA_C

ADCREQ_C [6:0]

ADCRES_C [9:0]

18 17 16 15 14 13 12 11 10 9 8 7

6543210

MOSI

x x x

ADCREQ_D [6:0]

MISO NEWDATA_D

ADCREQ_D [6:0]

ADCRES_D [9:0]

L9680 Datasheet(PDF) 217 Page - STMicroelectronics

L9680 Datasheet(HTML) 217 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

Datasheet Download

Link URL