5
iCE40 Ultra Breakout Board
Clock Sources
The board has a single 12 MHz clock source. The 12 MHz clock drives both the FTDI USB interface device, and the
iCE5LP4K device. The iCE5LP4K can be disconnected from the 12 MHz oscillator using J51. This is necessary, for
example, when iCE40 Ultra device ball C2 is mistakenly programmed as an output and prevents the FTDI USB
interface from operating.
Board Power
The board provides the following power features:
• Board Power
— Board power is derived from the USB connection.
— D3 Green LED indicates Board Power
• iCE40 Ultra VCC
— Onboard 1.2 V supply
— ICC can be measured across the series resistor R38 (1 Ohm) at TP10 and TP11
• iCE40 Ultra VCCIO
— Onboard 3.3 V supply
— ICC0 can be measured across the series resistor R14 (1Ohm) at TP1 and TP2
— ICC1 can be measured across the series resistor R96 (1Ohm) at TP8 and TP9
— ICC2 can be measured across the series resistor R15 (1Ohm) at TP3 and TP4
The power supplies on the iCE40 Ultra Breakout Board are simplified and suitable for booting from the external SPI
flash. The power supply sequencing does not conform to the NVCM boot requirements as specified in DS1048,
. The user may encounter intermittent boot success and/or higher than specified
startup currents when attempting to boot from NVCM.
Board Configuration and Programming
The board allows for programming of the iCE40 Ultra or the SPI Flash:
• SPI Flash Programming J10 shunt pins 1-3 and 2-4 (Default shunted)
— U7 Micron Technology Inc part number N25Q032A13ESC40F
• iCE40 Ultra Configuration or Programming J10 shunt pins 1-2 and 3-4
— U8 iCE5LP4K-SWG36
• CRESETB can be asserted by pushing SW1
— Can be probed with J2
• Done LED D2
— Can be probed with J3 (Default shunted)
Details of the iCE40 Ultra Board for use in programming are shown in Figure 3.
