Cs4202 – Cirrus Logic CS4202 User Manual

Page 40

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CS4202

DS549PP2

4.26

BIOS-Driver Interface Control Registers (Index 70h - 72h)

E[15:0]

Event Configuration. The E[15:0] bits control the BIOS-Driver Interface mechanism.

Default

0000h

The BDI Config Register (Index 70h)

enables BIOS-Driver communication for each possible event. If a bit is ‘0’, the

corresponding event will not be communicated. If a bit is ‘1’, the corresponding event will be communicated by as-
serting the BDI bit in input slot 12. If an event occurs, the BIOS will ‘set’ the corresponding bit in the BDI Status Reg-
ister (Index 7Ah). This bit remains ‘set’ until it is cleared by the driver, acknowledging the event has been handled.
This behavior is equivalent to “non-sticky” (level sensitive) GPIO input pins.

The BDI Wakeup Register (Index 72h)

provides a mask for determining if a BDI event will generate a wakeup or

GPIO_INT. If a bit is ‘0’, the corresponding event will not generate an interrupt. If a bit is ‘1’, the corresponding event
will generate an interrupt. Refer to the GPIO Pin Wakeup Mask Register (Index 52h) for details about wakeup inter-
rupts.

4.27

BIOS-Driver Interface Status Register (Index 7Ah)

E[15:0]

Event Status. This register, in conjunction with the BIOS-Driver Interface Control Registers
(Index 70h - 72h), controls the BIOS-Driver Interface mechanism.

Default

0000h

The BDI Status Register (Index 7Ah) reflects the state of all possible events. If a bit is ‘0’, the corresponding event

has not occurred or has already been handled by the driver. If a bit is ‘1’, the corresponding event has occurred and
has not been handled by the driver yet. The BDI bit in input slot 12 is a logic OR of all bits in this register ANDed
with their corresponding bit in the BDI Config Register (Index 70h). After handling an event, the driver should clear
it by writing a ‘0’ to the corresponding bit of this register.

D15

D14

D13

D12

D11

D10

E15

E14

E13

E12

E11

E10