SWRU629 September   2024

 

  1.   1
  2.   Description
  3.   Features
  4.   4
  5. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specification
    4. 1.4 Device Information
  6. 2Hardware
    1. 2.1 Wired Connections, Jumper Settings, Buttons, and LEDs
      1. 2.1.1  SWD Interface
      2. 2.1.2  I2C Connections
        1. 2.1.2.1 Default I2C Addresses
      3. 2.1.3  UART Signals
      4. 2.1.4  SD Card Interface
      5. 2.1.5  External Memory Interface
      6. 2.1.6  ADC Interface
      7. 2.1.7  Reset Pull-up Jumper
      8. 2.1.8  Push Buttons
      9. 2.1.9  LED Indicators
      10. 2.1.10 LaunchPad Header Pin Assignment
    2. 2.2 Power
      1. 2.2.1 VIO Selection
      2. 2.2.2 Measure the CC35xxE Current Draw
        1. 2.2.2.1 Low Current Measurement (LPDS)
        2. 2.2.2.2 Active Current Measurement
    3. 2.3 Clocking
    4. 2.4 Conducted RF Testing
    5. 2.5 Evaluation Setup
      1. 2.5.1 Wi-Fi Toolbox LP-EM-CC35X1 Hardware Setup
  7. 3Hardware Design Files
    1. 3.1 Schematics
    2. 3.2 PCB Layouts
    3. 3.3 Bill of Materials (BOM)
  8. 4Additional Information
    1. 4.1 Trademarks

2.1.5 External Memory Interface

The CC35xxE requires xSPI external flash memory for execution code, and supports adding optional external PSRAM on the same xSPI bus for additional runtime memory. The LP-EM-CC35X1 features an onboard external flash (U5) and a footprint for assembling an additional PSRAM (U6).

To use external PSRAM on the LP-EM-CC35X1, users must perform the following hardware changes:

  • Solder APS1604M-SQRX-SN PSRAM on the footprint U6.
  • R27 footprint on the front of the board must be populated with a 0 ohm resistor (0201).
  • R55 footprint on the front of the board must be populated with a 0 ohm resistor (0402).
  • R56-R60 footprints on the back of the board must be populated with 0 ohm resistors (0201).
LP-EM-CC35X1 External PSRAM Board (Top View) Figure 2-10 External PSRAM Board (Top View)
LP-EM-CC35X1 External PSRAM Board (Bottom View) Figure 2-11 External PSRAM Board (Bottom View)

The xSPI signals from the CC35xxE are part of the VDDSF IO ring, and this voltage can be defined as either 1.8V or 3.3V, depending on the external flash or PSRAM used. The default voltage of VDDSF on the LP-EM-CC35X1 is 1.8V. This voltage provides the reference voltage for the xSPI lines from the CC35xxE and supply voltage to the external flash and PSRAM.

If users want to use a flash or PSRAM which interfaces at 3.3V instead, then R42 can be assembled on the right two solder pads instead of the left (left pads = 1.8V, right pads = 3.3V). The R42 is on the left solder pads, therefore, the VDDSF voltage is 1.8V, as shown in Figure 2-10.