7. I
2
C Interface > Mailboxes
161
Tsi578 User Manual
June 6, 2016
Integrated Device Technology
www.idt.com
8.
C Internal Access Control Register”
to disable internal
register auto-incrementing.
I
2
C Sequence: <S><SLVA><W><PA=0x24><A><WD=0xA0><A><P>
Following the transaction, SLV_PA is 0x25,
is 0x000000A0, and interrupt status SA_OK asserts. An optional interrupt can also be
sent to the Interrupt Controller if enabled in SA_OK of
.
9.
“I2C_SCLK Low and Arbitration Timeout Register”
address (0x1D354) in
C Internal Read Address Register”
, then reads same register 3 times. The
register address no longer auto-increments, but the PA still auto-wraps from 0x17 to 0x14, so the
reads can be completed in a stream. Note that data is read from LSB to MSB.
I
2
C Sequence:
<S><SLVA><W><PA=0x10><A>
<WD=0x54><A><WD=0xD3><A><WD=0x01><A><WD=0x00><A><R>
<S><SLAV><W><A>
<RD=0x44><A><RD=0x33><A><RD=0x22><A><RD=0x11><A>
<RD=0x44><A><RD=0x33><A><RD=0x22><A><RD=0x11><A>
<RD=0x44><A><RD=0x33><A><RD=0x22><A><RD=0x11><N><P>
Following the transaction, SLV_PA is 0x14,
is0x001D354, and interrupt status SA_OK and SA_READ assert. An optional interrupt
can also be sent to the Interrupt Controller if enabled in SA_OK and SA_READ of
7.5.9
Resetting the I
2
C Slave Interface
The I
2
C slave interface is reset by two conditions: chip reset or the detection of a START condition.
When a chip reset is applied, the I
2
C slave interface immediately returns to the idle state. Any active
transfer, to or from the Tsi578 when the reset is asserted, is interrupted. All registers are initialized by a
full-chip reset.
As required by the
I
2
C Specification
, the Tsi578 resets its bus interface logic on receipt of a START or
repeated START condition such that it anticipates receiving a device address phase, even if the START
condition is not positioned according to the proper format. The I
2
C registers, however, are not reset.
7.6
Mailboxes
As part of the peripheral address space on the Tsi578, the following registers act as I
2
C mailboxes for
communicating information between an external I
2
C master and a processor or host:
•
for data incoming from an external I
2
C
master to the processor or host.
•
for data outgoing from the processor or host
to an external I
2
C master.