At the same time, the IC transfers to the microcontroller a 16-bit fault frame where the first 8 bits indicate a

channel fault (OVT) condition (each bit, set to ‘1’, indicates an OVT event), the following 4 bits provide general

fault condition information. FB_OK: this bit is related to the DC/DC regulation: at the DC/DC turn-on, this bit is low

and becomes high after FB rises above 90% of the nominal VFB voltage and a correct SPI communication

occurrs. If the FB voltage falls below 80% of the nominal VFB voltage, this bit is zero; TWARN (IC warning case

temperature), PC (parity check fail, the bit, set to ‘1’, indicates a PC fail or the length is not a multiple of 8), and

PG (Power Good, see Section 8.10). The last 4 bits are used as parity check bits and communication error

conditions (see command 16-bit frame):

P0 = F0

⊕F1⊕F2⊕F3⊕F4⊕F5⊕F6⊕F7

P1 = PC

⊕FB_OK⊕F1⊕F3⊕F5⊕F7

P2 = PG

⊕TWARN⊕F0⊕F2⊕F4⊕F6

nP0 = not P0

where

⊕istheXORoperatorsymbol.

Table 17. Fault 16-bit frame (from IC to MCU)

MSB

LSB

F7

F6

F5

F4

F3

F2

F1

F0

FB_OK

TWARN

PC

PG

P2

P1

P0

nP0

Channel indications are latched and cleared only after a communication.

9.3

Daisy chaining

The IPS8200HQ/HQ-1 can be daisy chained by connecting the MOSI port of the micro-controller to the SDI pin of

the first IC of the chain; the SDO pin of the first IC of the chain to the SDI pin of the second (and similarly for the

next ICs of the chain); and the SDO pin of the last IC of the chain to the MISO port of the micro-controller. See an

example in Figure 14

Figure 14. Example of daisy chaining connection

IPS8200HQ, IPS8200HQ-1

Daisy chaining

DS14313 - Rev 2

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