L9965TS datasheet(37/62 Pages) STMICROELECTRONICS

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The SPI frame sent to MCU (see Table 25) contains:

•

Bit 38: Compressed = 1

•

The DEV_ID of the particular L9965A addressed in the burst request

•

The Address feedback field:

–

0x38 to 0x49 (VCELLx_MEAS) depending on the enabled cells in L9965A. If a particular cell is not

enabled or it is configured as busbar (according to VCELL<x>_BB) the corresponding

VCELLx_MEAS register is not present in the FIFO

–

0x4A (BB_MEAS) if the Bus Bar measurement is enabled. If not enabled, the BB_MEAS register is

not present in the FIFO

–

0x4B (VBS_MEAS) if the VBS measurement is enabled. If not enabled, the VBS_MEAS register is

not present in the FIFO

–

0x4D to 0x56 (NTC_GPIO_MEAS_x) depending on the GPIO setting in L9965A. If a particular GPIO

is not enabled or it is masked the corresponding register is not present in the FIFO

•

The FAULT bit is set according to the GSW of the addressed L9965A

•

The DATA READ is composed according to the register structure (for more information, see the L9965A

datasheet)

•

The CRC of the frame.

In case of standard burst, single packet sent with an interframe time is received on VIF RX and is stored in FIFO

RX with the same approach of a single read.

5.8.2.3

Broadcast write

A broadcast write command allows simultaneous writing of the same data on all devices in a chain, or on a

subset.

The MCU can exploit different broadcast commands by programming the DEV_ID field of the SPI MOSI frame

(see Table 25). There are two types of broadcast commands, configured as described in table below:

Table 36. Broadcast commands

Type

DEV_ID

Purpose

Notes

Global

broadcast

0x0

•

Chain device addressing, for all devices in the

stack

•

Writing common configurations to all devices in

the stack

•

Executing common tasks for all devices in the

stack

•

Transceivers can

only be addressed

via SPI target

Selective

broadcast

0x3C +

BROADCAST_SEL_<x>

•

Writing common configurations to a specific

subset of devices in the stack

•

Executing common tasks to a specific subset of

devices in the stack

BROADCAST_SEL_<x> is a 2-bit field allowing sending commands to a subset of chained devices. The

command is accepted if the BROADCAST_SEL_<x> is equal to the BROADCAST_SEL_1 or

BROADCAST_SEL_2 in GEN_CFG1 register.

If the DEV_ID field of the frame is equal to a global or selective broadcast filter, the IC sends it to the VIF if the

SPI frame is correct (in terms of length, CRC).

The devices addressed are those programmed with matching BROADCAST_SEL_<x> value.

In both cases the next MISO frame is an echo of the SPI command (DEV_ID and Address).

The ICs on the VIF chain don’t generate answer upon receipt of broadcast commands.

The registers that can be addressed by broadcast write are reported in the registers map.

5.8.2.4

Read VIF received frames

All the frames received from VIF, already decompressed if necessary, are stored in the VIF RX FIFO.

The MCU accesses the frames in the RX FIFO:

1. With a single read/write frame (see Section 5.8.2.1).

L9965T/L9965TS

Functional description

DS14987 - Rev 1

page 37/62

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