Texas Instruments LP8580EVM, Руководство пользователя

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Using the LP8580EVM Evaluation Software
9 SNVU495 – March 2016
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Copyright © 2016, Texas Instruments Incorporated
LP8580 Evaluation Board
Figure 5. Evaluation Software
5.1 Digital Input Control
Controls in the digital input control area are used to control the digital input pins of the LP8580 IC. The
Enable button controls the state of the EN pin. The Interface button controls the state of the IFSEL pin.
The Addr1 button controls the state of the SS/ADDRSEL pin when LP8580EVM is set up for I2C mode.
Dimming control can be used to control the SDO/PWM pin when LP8580EVM is set up for I2C mode. This
can be used for PWM brightness control. The PWM frequency and duty cycle can be set, and the PWM
generator can be turned on and off. The
Update button needs to be pressed to update new frequency or
duty cycle to the PWM generator.
V
SYNC
control can be used to control the VSYNC pin. The V
SYNC
frequency and duty cycle can be set and
the V
SYNC
generator can be turned on and off. The Update button needs to be pressed to update new
frequency or duty cycle to the V
SYNC
generator.
H
SYNC
control can be used to control the HSYNC pin. The H
SYNC
frequency can be set, and H
SYNC
generator
can be turned on and off. Update button needs to be pressed to update new frequency to the V
SYNC
generator.
5.2 Interface Selection
The LP8580 supports both SPI and I2C interfaces. The interface is selected with the IFSEL pin of the
LP8580. In I2C mode the LP8580 supports two I2C slave addresses (0x2C and 0x3C). The LP8580 I2C
address is selected with the SS/ADDRSEL pin. Before LP8580 registers can be read or written, hardware
settings and evaluation software interface selection must be set correctly. The
Interface and the Addr1
buttons control the digital input pins of the LP8580, and Interface selection controls how the onboard
microcontroller communicates with the LP8580 IC.
To use the SPI interface, shunts of the IC must be set as shown in Figure 6 . The Interface button in the
digital control area of the evaluation software must be in OFF state, and SPI must be selected in the
interface selection area.