Numark D2 Director, Service Manual

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Serial ports
The ARM CPU provides 3 serial ports, of which we make use of 2. TXD0/RXD0 are used for
debugging purposes, and this serial port is accessible on the NH00 I/O board. TXD1/RXD1 are not
used on the NH00 (on KA3 it is used for the iPod interface). RXD2/TXD2 are not used as a serial
port; TXD2 is a simple control signal as mentioned earlier.
Display interface
The ARM CPU drives the LCD module using the following signals:
Signal name Function
SPCLK Pixel clock
VSYNC Vertical sync signal
HSYNC Horizontal sync signal
BLANK Blanking signal
BRIGHT Pulse width modulated (PWM) signal controls brightness of LCM backlight
P17 Used for frame reverse signal
P12/P8/P4/P0 Used for D0..D3 4 bit video data
Status LEDs
D1 (red) and D2 (green) are status LEDs that can be used to see if the CPU has booted correctly.
Normally, the red LED will light briefly at power up then the green one will come on instead.
If this fails to happen it indicates that the CPU has failed to boot for some reason.
SHEET 2 – I/O & PSU
This sheet shows the I/O connections, power supplies and power control.
Connections to I/O board
PL2-3 are 50 way high density connectors that connect the various signals to the I/O board:
I2S audio signals
I2C bus
SPI bus
LCD interface
Serial ports
Power control signals (OFF, POWER, POWERFAIL)
Codec reset signals (ADC_RESET, DAC_RESET)
USB ports
The 3 USB ports are provided on PL4-6. USB host ports are required to provide a 5V power supply.
IC9 is a protection device that is designed to protect the system from faults in the external USB
devices. It limits the current to a maximum of 0.9A per port, and detects short circuits. If a fault
occurs, !USBFAULT will go low. This is buffered by IC7 and reported back to the CPU. The
power for the USB ports can be turned off by the CPU using GPIO13.
IC8 is an analogue switch that switches the USB signals for one of the ports. In the KA3, PL6 is
connected to the iPod dock, and the analogue mux can disable the USB port when the iPod is used
in serial mode. In NH00, PL6 is a normal USB port, so IC8 will always pass the USB signals.
PL9 is for the iPod serial port which is not used in NH00.