L99UDL01 datasheet(58/88 Pages) STMICROELECTRONICS

58 / 88 page

Programmers guide

L99UDL01

58/88

DS12511 Rev 5

If OUT1 and OUT2 are grouped (GRP1_2 bit is set in register 03H) OUT1_on can be used

to command these two outputs on. OUT2_on will be ignored if used.

In normal mode, all overridden outputs (internal and external) will experience a ~6us pause

at each write access to register 01h that does not set the OUT_ON control bit. In emergency

mode, all overridden outputs (internal and external) will experience a ~10 µs pause at each

write access to register 01h regardless of the OUT_ON control bit value. Once back in

normal mode from the emergency one, the behavior will remain the one described in

emergency mode, unless the overridden outputs are disabled and then enabled again.

EMCYx

Emergency mode overrides any current actuation command in progress and drives outputs

according to the programmed values in the registers. If OUT_ON is low on the rising edge of

CSN then all timed actuation activity (if a timed actuation is in progress) will stop and wait for

an actuation.

While in Emergency mode the status bits (STAT[1:0]) will be automatically cleared whenever

there is a write to CR01H.

This command also overrides all protections such as thermal shutdown and overcurrent

latch off. In Emergency mode the device will not latch off if an overcurrent threshold is

exceeded. Instead of latching off the driver and reporting a fault the output will continue to

retry as in Normal mode. All faults will be reported while not acted upon.

Emergency mode is initiated when a (1, 0) is entered in the EMCY bits. All other EMCY bit

configurations result in Normal mode. Emergency mode is exited by initiating another

actuation where the EMCY bits are different from (1,0) or because of V3V3RST event.

At the initiation of an emergency mode timed actuation a ~10 µs pause will be experienced

on all overridden outputs (internal and external). In case of indefinite braking, at the initiation

of an emergency mode timed actuation a ~10 µs pause will be experienced on all outputs

(internal overridden, external overridden and time actuated)

EXTx_LSD, EXTx_HSD

These bits determine the polarity of an output, i.e. they specify which is the driver switched

on, High Side or Low Side. External drivers cannot be PWMmed.

Table 31. 01H emergency command description

EMGCY bits

Bit 1

Bit 0

Mode

Normal mode

Emergency mode

Normal mode

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