Digilent Genesys ZU Reference Manual page 40

Write transaction example. Let's say the PC wants to clear all system faults. For this, it will send to the
Platform MCU:
Byte 0: 1E (i.e. Bits 7‐1 = 0x0F which is the address of Platform MCU register; Bit 0 = '0' meaning write
transaction)
Byte 1: 01 (i.e. the PC want to write 1 byte)
Byte 2: 02 (value to write to register at address 0x0F ‐ Clear all faults)
Read transaction example. Let's say the PC wants to read Fan Speed Faults register from the Platform
MCU. For this, it will send to the Platform MCU:
Byte 0: 0D (i.e. Bits 7‐1 = 0x06 which is the address of Fan Speed Fault register; Bit 0 = '1' meaning read
transaction)
Byte 1: 01 (i.e. the PC wants to read 1 byte)
The Platform MCU will then send 1 byte back to the PC, containing the value of the Fan Speed Fault
register.
To read a 16‐bit register like Measured Fan Speed the PC will send to the Platform MCU:
Byte 0: 09 (i.e. Bits 7‐1 = 0x04 which is the address of Measured Fan Speed register; Bit 0 = '1' meaning
read transaction)
Byte 1: 02 (i.e the PC wants to read 2 bytes)
The Platform MCU will then send 2 bytes back to the PC. The first byte that is sent is the least significant
one. If one receives 150C one have to swap the first byte with the second one and to convert the value
to decimal: 150C → 0x0C15 → 3093 RPM.
The UART baudrate should be set to 115200/8/E/1 (115200 baud, 8 data bits, even parity, 1 stop bit).
10.2.2. Bootloader Section
In the program memory, along with the Firmware Application, there is a bootloader that launches the
Application at power‐up.
10.3. Fan
Mounted on the MPSoC heatsink, there is a 12 V fan with a 4‐pin header. It can automatically be
controlled by the Platform MCU based on the MPSoC temperature or set to the fixed full speed. This
option is controlled by JP2 and is user‐selectable.