7. I
2
C Interface > Block Diagram
144
Tsi578 User Manual
June 6, 2016
Integrated Device Technology
www.idt.com
7.3
Block Diagram
shows an overview of the I
2
C Interface. The shaded area is the block logic. The master and
slave interfaces mux between control of the I2C_SD and I2C_SCLK I/O buffers, and connect through
the package to the buses on the board. The reference clock (P_CLK) and active-low hard reset are
inputs to the block. The power-up reset values are either static signals from outside the block, or
connect to package pins for board-level configuration. The I2C_MA pin is a power-up configuration
pin that is latched during reset.
On the core side, the I
2
C block connects to the internal device register bus as a slave and master:
•
As a slave, it enables access to the I
2
C block registers by a host or processor.
•
As a master, it enables access to other device registers (for example, during the I
2
C load at
power-up).
In addition, various signals relate to the boot load sequencer, an interrupt signal connects to the Tsi578
Interrupt Controller, and device-level status connects to the EXI2C_STAT register in the externally
visible registers.