MSP430F5342: MSP430F5342 With Microwire Interface

Sujith Mohandas

Part Number: MSP430F5342
Other Parts Discussed in Thread: LMK04808

Tool/software:

Hi Team,

I'm using MSP430F5342IRGZR microcontroller in my design.I wanted to interface MSP430F5342IRGZR with LMK04808.I have gone through the LMK04808 datasheet, looks this device has microwire interface for configuration. But i couldn't find any dedicated Microwire interface pins on MSP430 to interface other slaves device. My intention is program the LMK04808 via MSP430.
Could you please check and confirm how can i interface the MSP430F5342IRGZR with LMK04808. Can we connect LMK04808 Microwire signals to MSP430F5342IRGZR SPI controller? Please refer attached image
Does this work out?

/resized-image/__size/1000x1000/__key/communityserver-discussions-components-files/166/pastedimage1723483075385v3.png

Regards,
Sujith M

over 1 year ago

0 Keith Barkley over 1 year ago

Guru 43635 points

It looks to be an ancient SPI-like protocol. The tricky part is that it is half duplex. you will probably have to use some dummy transmits to receive.

0 Bruce McKenney over 1 year ago in reply to Keith Barkley

Guru 102835 points

I think the half-duplex is a property of the upper layer; it's not a 3-wire (shared SIMO/SOMI), just an ordinary SPI. The readback is 27 bits, but I suspect you could read 32 bits (SPI clocks) and shift it right 5 bits.

I think you want DATAuWire connected to SIMO.

LEuWire is /CS, which is related to STE but STE won't do what you want. You can use the UCB0STE pin (or any other pin) but you should drive it as a GPIO.

0 Keith Barkley over 1 year ago in reply to Keith Barkley

Guru 43635 points

By "half-duplex" I meant that it did not tx/rx at the same time. You covered the issue well.

0 Sujith Mohandas over 1 year ago in reply to Keith Barkley

Prodigy 190 points

Hi Ti Experts,

Does MSP software can handle the Microwire interface if configure as below scheme. I'm fresh in the design of MSP. We need your confirmation to sign of the design, To enable MSP microwire interface what has to enabled on the MSP430 Software side?

/resized-image/__size/1000x1000/__key/communityserver-discussions-components-files/166/pastedimage1723556446026v1.png

Regards,
Sujith M

0 Bruce McKenney over 1 year ago in reply to Sujith Mohandas

Guru 102835 points

To do readback, you'll probably want to connect UCB0SOMI to the status_HOLDOVER pin [Ref datasheet (SNAS489K) Sec 8.5.3]

There is one unusual transaction calling for 3 "extra" clocks (the SPI unit works in multiples of 8), but those clocks can be supplied as a matter of course by the subsequent transaction so this "special" case may take care of itself [Ref datasheet Sec 8.5.1 and 8.3.2].

A simple SPI example is here:

https://dev.ti.com/tirex/explore/node?node=A__AP1EwffnpXqyq1S7FBSEzA__msp430ware__IOGqZri__LATEST

It uses UCA0 rather than UCB0, but they're pretty much the same when used for SPI.

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MSP430F5342: MSP430F5342 With Microwire Interface