UPSD33XX Datasheet, PDF (95/231 Pages) STMicroelectronics – Fast 8032 MCU with Programmable Logic

I²C INTERFACE
uPSD33xx devices support one serial I²C inter-
face. This is a two-wire communication channel,
having a bi-directional data signal (SDA, pin P3.6)
and a clock signal (SCL, pin P3.7) based on open-
drain line drivers, requiring external pull-up resis-
tors, R_P, each with a typical value of 4.7kΩ (see
Figure 38).
I²C Interface Main Features
Byte-wide data is transferred, MSB first, between
a Master device and a Slave device on two wires.
More than one bus Master is allowed, but only one
Master may control the bus at any given time. Data
is not lost when another Master requests the use
of a busy bus because I²C supports collision de-
tection and arbitration. The bus Master initiates all
data movement and generates the clock that per-
mits the transfer. Once a transfer is initiated by the
Master, any device addressed is considered a
Slave. Automatic clock synchronization allows I²C
devices with different bit rates to communicate on
the same physical bus. A single device can play
Figure 38. Typical I²C Bus Configuration
VCC or VDD(1)
I2C BUS
SDA
SCL
RP
RP
uPSD33xx
the role of Master or Slave, or a single device can
be a Slave only. Each Slave device on the bus has
a unique address, and a general broadcast ad-
dress is also available. A Master or Slave device
has the ability to suspend data transfers if the de-
vice needs more time to transmit or receive data.
This I²C interface has the following features:
– Serial I/O Engine (SIOE): serial/parallel
conversion; bus arbitration; clock generation
and synchronization; and handshaking are all
performed in hardware
– Interrupt or Polled operation
– Multi-master capability
– 7-bit Addressing
– Supports standard speed I²C (SCL up to
100kHz), fast mode I²C (101KHz to 400kHz),
and high-speed mode I²C (401KHz to
833kHz)
Device with I2C
Interface
SDA/P3.6 SCL/P3.7
uPSD33XX(V)
Device with I2C
Interface
Note: 1. For 3.3V system, connect R_P to 3.3V V_CC. For 5.0V system, connect R_P to 5.0V V_DD.
Device with I2C
Interface
AI09623
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