L9963E datasheet(86/184 Pages) STMICROELECTRONICS

86 / 184 page

4.12.2

Routine execution modes

The voltage conversion routine can be executed in three different ways according to microcontroller commands.

The different modes are mutually exclusive: only one routine execution at a time is allowed and multiple threads

are not supported.

Figure 23. Routine execution modes: on-demand and cyclic executions

The execution modes follow a priority concept:

•

Configuration Override has high priority, since its purpose is to perform diagnostics upon failure detection

in order to validate the catch. It can interrupt any ongoing activity and, once done, Voltage conversion

routine is moved to Idle state, waiting for the microcontroller to interpret the diagnostic data.

•

On-Demand Conversions have low priority. They are meant to allow microcontroller performing

measurements or diagnostics at specific time instants. They cannot co-exist with Cyclic Conversions:

to run an on-demand conversion, cyclic conversions have to be disabled and MCU has to wait for their

termination (monitor the DUTY_ON flag). On the other hand On-Demand Conversions cannot interrupt

themselves, nor a Configuration Override.

•

Cyclic Conversions have low priority. Their purpose is mainly to monitor battery pack and L9963E status.

However, they can also be used to periodically retrieve measurement data. They can be interrupted by

Configuration Override. They cannot co-exist with On-Demand Conversions: before enabling cyclic

conversions, MCU must wait for any ongoing on-demand conversion to end first (monitor the DUTY_ON

flag).

In general, microcontroller is able to determine L9963E activity by performing a read operation on the

ADCV_CONV register and observing the following bit:

Table 56. Voltage conversion routine status

SOC (status

upon readback)

OVR_LATCH CONF_CYCLIC_EN DUTY_ON

Device status

Idle

Not possible

L9963E

Voltage conversion routine

DS13636 - Rev 12

page 86/184

L9963E Fiches technique(PDF) 86 Page - STMicroelectronics