NCV7520
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Table 10. DIAGNOSTIC CONFIG 2 REGISTER
R3
A2 A1 A0 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 P
0 1 1 X X X X X
X
CH5 CH4 CH3 CH2 CH1
CH0
?
1 = ENABLE DIAGNOSTIC
DEFAULT = ENABLE
OPEN LOAD DIAGNOSTIC ENABLE/DISABLE
Diagnostic Status Registers − Register R4 & R5
Diagnostic status and ENB status information is returned
when R4 or R5 is selected (Table 11) Diagnostic status
information for each channel is 3−bit (ST2:0) priority
encoded (Table 12). Bit D[9] returns the state of the ENB
input e.g. D[9] = 0 when ENB = 0 (enabled). Status is latched
for the currently higher priority fault and is not demoted if
a fault of lower priority occurs. The latched status is not
affected by ENB. Default response after reset is D[8:0] = 1
(“Diagnostic Not Complete”).
When a channel is configured for auto−retry mode, its
status register bits are reset to “Diagnostic Not Complete”
after reading the register (see Figure 18).
When a channel is configured for latch−off mode and no
“SCB” status is present, its register bits are reset to
“Diagnostic Not Complete” after reading the register. If
“SCB” status is present, its register bits are set to “GLO”
after reading the register. This status is maintained until the
channel is un−latched either by successfully executing the
un−latch sequence or by disabling then re−enabling the
device via the ENB input (Figure 18). The “GLO” status
allows the application to detect a latched−off channel in the
event the “SCB” status data is discarded by the controller
due to SPI transmission error.
Table 11. DIAGNOSTIC STATUS REGISTERS
A2 A1 A0 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 P
R4
1 0 0 X X X X X X X X X X X X ? SI
1 0 0 0 0 ENB CH2 CH1 CH0 CH2 CH1 CH0 CH2 CH1 CH0 ? SO
R5
1 0 1 X X X X X X X X X X X X ? SI
1 0 1 0 0 ENB CH5 CH4 CH3 CH5 CH4 CH3 CH5 CH4 CH3 ? SO
ST2 ST1 ST0
Table 12. DIAGNOSTIC STATUS ENCODING
ST2 ST1 ST0 STATUS PRIORITY
0 0 0 GLO – GATx LATCHED OFF 0 HIGHEST
0 0 1 SCB − SHORT TO BATTERY 1
0 1 0 SCG − SHORT TO GROUND 2
0 1 1 OLF − OPEN LOAD 3 (Note)
1 0 0 Diagnostic Complete − No Fault 4
1 0 1 No SCB Fault − ON State 5
1 1 0 No SCG/OLF Fault − OFF State 6
1 1 1 Diagnostic Not Complete (DEFAULT) 7 LOWEST
NOTE: OLF status report is suppressed when open load diagnostic is turned off via
Diagnostic Config 2 − register R3
Revision Information − Register R6
Device revision information is returned when R6 is
selected (Table 13). Output bits D[11:8] are hard coded to 0,
bits D[7:6] are encoded with the specific device identifier
(i.e. “00” = 7518, “01” = 7519, “10” = 7520), bits D[5:3] are
hard coded with the die (silicon) revision, and bits D[2:0] are
hard coded with the mask (interconnect) revision. The first
response frame sent after reset is the device revision
information. The revision encoding scheme is shown in
Table 14.
Mask revision may be incremented when an interconnect
revision is made. Die revision is incremented when a silicon
revision is made. Mask revision is reset to “000” when a die
revision is made.