ZAMC4100 Datasheet, PDF (74/155 Pages) Integrated Device Technology – Actuator and Motor Controller

ZAMC4100 Datasheet
Table 3.9). Recovering from that state to normal functionality requires that the ECMOCIF flag to be cleared by
writing “1” to its position in the ECMDIAG register. The procedure for recovering from that state to normal
functionality goes through the following steps:
As previously discussed, it is strongly recommended that the MCU performs an open/short diagnostic check
before re-enabling the driver:
• If the result is “Normal load or short to VSS” (see section 3.11.3), then “Normal load” condition is
assumed and the MCU should proceed with the driver enable. If enabling the driver generates an over-
current event, then there is a “short to VSS” failure at the output.
• If the diagnostic (and eventual activating of the driver as described above) results in “short to VSS,”
“Short to VDDE,” or “Open load,” the ECM driver should not be enabled until the failure is present.
ECM “Short to VSS” and “Short to VDDE” Failures
For ZAMC4100 failures for the ECM, “Short to VSS” and “Short to VDDE” must be considered differently on the
module level compared to the ZAMC4100 level. On the module level, the short failures are defined for each point
in the outside circuitry, including external connections, components and loads, and reflect their specifics. On the
ZAMC4100 level, failure is defined inside the IC, also including the pins on the package.
This clarification is important because module-level failures are not always IC-level failures. For example in the
case of a “Short to VSS” of the EC mirror terminal (module-level failure), the current through the output of the
ECM driver is limited by the external resistor R1 (see the application diagram in Figure 6.1) to a value in the
normal operation range for the ZAMC4100 (see parameters I_{OC_EC_M} and I_{OC_EC_RES} in Table 1.9). As a result, this
particular event will not be detected by the internal over-current protection circuitry of the ECM driver and no over-
current event will be detected and captured in the ECMOCIF interrupt flag (see section 3.11.3,
© 2016 Integrated Device Technology, Inc.
74
January 26, 2016