I3C bus extension products provide 12.5 MHz speeds

News | June 8, 2020

By Ally Winning

Interconnect & cables

The new products are the IMX3102 2:1 bus multiplexer, IMX3112 1:2 bus expander, and IXP3114 and IXP3104 1:4 general-purpose IO expanders. The devices support speeds of up to 12.5MHz and feature integrated thermal sensor capability.

The four new devices have been developed to offer maximum design flexibility for the implementation of I3C Basic as a system management bus in applications that may have multiple masters, many endpoint devices, and long traces. All three can impact bus complexity and signal integrity. The devices have an integrated thermal sensor to allow better integration of thermal management into the bus design and make it possible to reduce the number of thermal sensor endpoints. Next-generation compute architectures will see the transition to I3C as the system management bus of choice after the JEDEC standard adoption of I3C Basic for the DDR5 memory sideband. Increasing memory subsystem complexity and distributed power management, telemetry and thermal management at the sub-channel level needs a higher sideband bus bandwidth.

Emerging needs for advanced thermal control loops, security and component authentication, along with the need for more robust fault tolerance and recovery drive the requirement for a high bandwidth interface across the whole server control plane. I3C Basic serves all of these needs. The protocol allows system management architectures to provide granular information about the server resource status during bootup and runtime.

Renesas I3C Basic Expanders

The IMX3102 2:1 bus multiplexer has been developed for designs where there may be two masters controlling a single peripheral or slave devices. The IMX3112 1:2 bus multiplexer is intended for designs that feature a single host controlling two peripheral or slave devices. The general-purpose IO expanders, IXP3114 (with temperature sensor) and IXP3104 1:4 (no temperature sensor) have been developed for a host controller with up to four peripheral or slave devices.

Positioning temperature sensors in multiple locations on the motherboard allows continuous monitoring for potential temperature spikes allowing the CPU to take action to prevent catastrophic events.

Additional features include:

• Two-wire programmable I2C or I3C Basic bus serial interface

• Single device load on the host bus

• Single 1.8V input power supply

• Integrated temperature sensor accuracy: 0.5°C with 0.25°C resolution

• Industrial temperature range: -40°C to 125°C

• Packet error check and parity error check functions

• Bus reset and bus clear functions

• In-band interrupt

• Programmable I2C, I3C Basic bus address

• 2mm x 3 mm, thermally enhanced 9-pin PSON-8 package

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