UPSD3354DV-40U6 Datasheet, PDF (122/272 Pages) STMicroelectronics – fast 8032 MCU with programmable logic

I²C interface
23 I²C interface
UPSD33xx
UPSD33xx devices support one serial I²C interface. 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 resistors, R_P, each with a
typical value of 4.7kΩ (see Figure 37).
23.1 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 detection and arbitration. The bus Master initiates all data movement
and generates the clock that permits 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 the role of Master or Slave, or a single device can be a Slave only. Each Slave}
t(s ^{device on the bus has a unique address, and a general broadcast address is also available.}
A Master or Slave device has the ability to suspend data transfers if the device needs more
c _{time to transmit or receive data.}
du _{This I2C interface has the following features:}
ro _{● Serial I/O Engine (SIOE): serial/parallel conversion; bus arbitration; clock generation}
P _{and synchronization; and handshaking are all performed in hardware}
te _{● Interrupt or Polled operation}
le _{● Multi-master capability}
so ● 7-bit Addressing
b _{● Supports standard speed I2C (SCL up to 100kHz), fast mode I2C (101kHz to 400kHz),}
O _{and high-speed mode I}2_{C (401kHz to 833kHz)}
t(s) ^{- Figure 37. Typical I2C bus configuration}
c ^{VCC or VDD(1)}
lete ^{Produ I2C BUS}
SDA
SCL
RP
RP
Device with I2C
Interface
Obso ^{SDA/P3.6 SCL/P3.7}
Device with I2C
Device with I2C
UPSD33XX(V)
Interface
Interface
1. For 3.3 V system, connect R_P to 3.3 V V_CC. For 5.0 V system, connect R_P to 5.0 V V_DD.
AI09623b
122/272
Doc ID 9685 Rev 7