NXP Semiconductors PCA9959HN-ARD, Руководство пользователя, Страница: 20 / 32

NXP Semiconductors
UM11623
PCA9959HN-ARD evaluation board
• Select COM Port displays the port selected for the communication. The port is
automatically selected by the system and is shown here as ( COM3 , Figure 12 ).
• Select Board
allows the user to select the correct daughter board (the application can
support three different boards). In Figure 12 , the selected board is
PCA9959
. Selecting
the wrong EVK or daughter board, causes the connection to fail and a pop-up window
with the message: “ Unable to Connect with Daughter Card ” appears on the screen.
Click
Connect
to establish the connection with the EVK.
Device Setting
parameters are:
• REXT Settings
selects the maximum current delivered by the LED drivers. This
selection is determined by the status of switch U4 on the PCA9959HN-ARD board (see
Section 5 "Getting to know the hardware" ).
OE controls the OE input of the DUT.
• SPI Frequency selects the bus speed. The drop-down box allows the selection of four
values: 100 kHz, 1 MHz (default value), 4 MHz, and 10 MHz.
Clicking the Set All button at the bottom of the section causes the selected values to be
set in the daughter board. Clicking Reset Chip returns the DUT's internal registers to
their default values.
The PCA9959 device’s internal controller has many 8-bit registers that provide detailed
control, and error management. The internal registers are organized in four groups
of LED gradation control, each LED channel being assigned to one of groups. For
each group, PCA9959 supports 64-grid gradation brightness control, allowing for each
LED output to be on with individual preset current value, or off. The GUI application is
reflecting the PCA9959, allowing the user to set the values of the registers, without any
constraint. Therefore, the user must fully understand the internal register map of the
PCA9959 device. Additionally, in Section 9 "Operation example" a set of instructions
are provided, to help the user for quick check of the PCA9959HN-ARD board and
understanding how to write the internal registers of the PCA9959 device.
General Settings
The displayed parameters in the section, belongs to internal registers “MODE1” and
“MODE2” (00h, and 01h). See the PCA9959 device data sheet for bit level details
regarding the mode registers. Set the values for each parameter and click the Write
button to update the PCA9959 mode registers with the desired configuration. The Read
button brings back the data from the mode register to GUI interface. The status bar
located in the bottom side of the interface shows the connection status between the PC
and the EVK.
Note:
Due to high complexity of the internal register map and functions of PCA9959HN
IC, for proper operation and testing of the daughter board from GUI application, the user
should read in detail the data sheet of PCA9959 IC.
UM11623 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2021. All rights reserved.
User manual Rev. 1 — 21 May 2021
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