What is I2C timeout?
The Bus Free Timeout is an error recovery mechanism that will allow the SMBus or I2C state machine to consider the bus “free” whenever the SDA and SCL lines are both high for more than 10 SMBus clock source periods or the configured I2C bus free timeout period.
How long can an I2C wire be?
So the maximum bus length of an I2C link is about 1 meter at 100 Kbaud, or 10 meters at 10 Kbaud. Unshielded cable typically has much less capacitance, but should only be used within an otherwise shielded enclosure.
What is the max speed of I2C?
Characteristics
| Wires | 2 (SCL and SDA) |
|---|---|
| Data Frame Size | 8 Bits packets |
| Maximum speed | Standard mode = 100 Kbps |
| Fast Mode = 400 Kbps | |
| High-Speed mode = 3.4 Mbps |
What is stop condition in I2C?
The use of this so-called “repeated start” is common in I2C. A Stop condition ALWAYS denotes the END of a transmission. Even if it is issued in the middle of a transaction or in the middle of a byte.
Is I2C good for long distance?
Indeed, I2C is not made for “long distance” communication….
Why is I2C better for long distance?
I2C has some extra overhead due to start and stop bits. I2C supports multiple devices on the same bus without any additional select lines (work on the basis of device address). SPI requires additional signal (slave select lines) lines to manage multiple devices on the same bus. I2C is better for long-distance.
Why is I2C so slow?
I2C: all lines are open-collector which means that the transmitter only drives the line low. When the transmitter releases the line, a resistor connected to Vcc (supply voltage) pulls the light high. However, due to capacitance of the wire and the components, the wire goes to high voltage relatively slowly.
Which is better I2C or SPI?
Overall, SPI is better for high speed and low power applications, while I2C is better suited for communication with a large number of peripherals, as well as in situations involving dynamic changing of the primary device role among peripherals on the I2C bus.
What is 12c start condition?
Understanding the I2C Bus. 2.1.1. START and STOP Conditions. I2C communication with this device is initiated by the master sending a START condition and terminated by the master sending a STOP condition. A high-to-low transition on the SDA line while the SCL is high defines a START condition.
What is clock stretching in I2C?
Clock stretching allows an I2C slave device to force the master device into a wait state. A slave device may perform clock stretching when it needs more time to manage data, such as store received data, or prepare to transmit another byte of data.
Is there a maximum clock speed for I2C?
It is not necessary to actually use those speeds; in normalmode there is no reason that we could not use a 50kHz clock (100kHz is the maximumspeed in normal mode and for this reason it is usually stated that this can run at rates up to100kHz). It is also important to note that I2C is specified down to DC so there will notbe a maximum time.
Who is the author of the I2C bus specification?
Specification. Initially the I2C Bus specification had been written by Philips Semiconductors. This company became NXP Semiconductors which now it the stakeholder of the I2C bus specification. Recent Version. I²C-bus Specification, Version 6.0, 4th of April 2014 This is the I2C reference.
What happens after the start of the I2C bus?
After the Start condition the master can generate a repeated Start. This is equivalent to a normal Start and is usually followed by the slave I2C address. Microcontrollers that have dedicated I2C hardware can easily detect bus changes and behave also as I2C slave devices.
How are rise and fall times defined in I2C?
Figure 1: I2C Fast Mode Timing Definition Rise (tr) and Fall (tf) Times t r is defined as the amount of time taken by the rising edge to reach 70% amplitude from 30% amplitude for either SDA and SCL, while t f is defined as the amount of time taken by the falling edge to reach 30% amplitude from an amplitude of 70%. Figure 2: Rise and Fall Time