ZAMC4100 datasheet(74/156 Pages) RENESAS

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ZAMC4100 Datasheet

January 26, 2016

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 IOC_EC_M and IOC_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,

ZAMC4100 Datasheet(PDF) 74 Page - Renesas Technology Corp