Jumper Settings
2-6 Blackfin Landscape LCD EZ-Extender Manual
JP5 adds flexibility to the extender: you can control the LCD display reset
by one of three available methods. By default, JP5 is populated so that the
EZ-KIT Lite/EZ-Board reset pin connects to the reset pin of the LCD dis-
play (P1.28). Consequently, a reset supervisory circuit located on the
EZ-KIT Lite/EZ-Board controls the reset pin going to the LCD display
(see Table 2-4).
To control the LCD display reset via software, write to the respective
AD7147 (U3) control registers using the 2-wire interface (TWI) of the
processor and control the AD7147 GPIO pin.
When using the expansion interface II (EZ-Boards), you can also control
the LCD display reset via the GPIO4 flag pin. GPIO4 connects directly to
the processor and LCD display, and can be controlled without the need to
communicate to the AD7147 controller. The GPIO4 pin is unavailable on
the PPI stamp connector; as a result, when using a PPI connector, you can
not use GPIO4 to control the LCD display reset.
PPICLK Disable Jumper (JP6)
The PPICLK disable jumper (JP6) disables and tri-states the buffer (U4) that
drives the 5 MHz clock coming from the on-board oscillator (U2). The
buffer is powered via the V_Select pin and used for level translation of the
3.3V oscillator to the VDDIO coming from the EZ-KIT Lite/EZ-Board.
Use JP6 to disable the buffer if the PPI clock is generated via the Blackfin
processor. This tri-states the 5 MHz clock driven by the buffer and pre-
vents any signal contention issues. By default, JP6 is not populated, and
the 5 MHz clock is driven to the PPI clock line (see Table 2-5).
Table 2-4. JP5 Settings
Functionality JP5 Setting
EZ-KIT Lite/EZ-Extender reset connected to LCD reset JP5.1 and JP5.2 (default)
AD7147 GPIO pin connected to LCD reset
JP5.3 and JP5.4
GPIO4 pin connected to LCD reset JP5.5 and JP5.6
