Summary

During this sprint, I worked on setting up the Cypress Static RAM chip on a VR table with an Arduino microcontroller and Raspberry Pi to power the chip and manipulate it using an Arduino program that I am developing with the help of Tom Claflin at the Leahy Center.

Setting Up the Chip

The goal with the Cypress Static RAM chip is to attempt to read data from it. The data sheet provided for this chip states that in order to read from the chip, the Chip Enable (CE) and Output Enable (OE) pins must be set to LOW, and the Write Enable (WE) pin must be set to HIGH. Then, the Byte Low Enable (BLE) pin can be set to LOW. Once these actions are performed, a memory address can be specified on one of the address (A) pins and the data at that address will be outputted to one of the Input/Output (I/O) pins. These instructions from the data sheet can be seen below:

These pins can be identified using the diagram provided in the data sheet, as seen below:

In order to read from this chip without soldering it, I will be connecting the chip to a VR table. This device has articulated arms with pins on the end of each that can be moved to connect to the pins on the chip. These arms are then wired to connect to pins at the base of the table that can be wired to other devices. This usage was previously discussed in the methodology for this device's testing.

The pin's numbers are usually determined by a small dot in one of the corners on the top of the chip indicating which pin is the first. Once that dot was located, I was able to orient the chip on the VR table according to the diagrams provided by the data sheet that indicate the pin positioning when the chip is being viewed from the top and from the bottom.

This flips the pin order shown in the previous diagram.

The chip set up on the VR table is seen below:

In addition to the pins mentioned in the data sheet, ground (Vss) and voltage (Vcc) also had to be connected to the VR table so the chip could be powered properly. The data sheet specifies that the chip has a voltage range of 1.65V to 2.25V, and the VR table has a built-in power option of 1.8V, so I could connect the voltage pin to power directly through the VR table.

Manipulating the Chip

Now that the chip is attached to the VR table, it can be connected to the Arduino microcontroller. As previously discussed in the methodology for this device, the Arduino microcontroller allows me to create and run programs to manipulate the chip. The current version of this program is available here.

Moving Forward

The next step is to test the Arduino program on the chip. I will connect the chip to a breadboard, then to the Arduino microcontroller, and connect the Arduino to my computer to run the program from the Arduino IDE. If the chip is connected correctly and the program works properly, I will be able to read from the first memory address. Then, I can modify my FOR loop calling the send_address function to read from more memory addresses and pull data from the chip.