Datasheet

Application Note AN-1006
Rev. A | Page 5 of 16
Multiple Address Operation with SPI Combined Multiple Latch and Multiple Address
Operation with SPI
The USBi can support up to two identical devices on the same
SPI latch if the SPI address pins of the target devices are indepen-
dently set to two different addresses, matching the addresses in
the drop-down box in the Hardware Configuration tab of
SigmaStudio.
A combination of multiple latch and multiple address schemes
can be used, but the total number of devices cannot exceed five.
CONTROLLING THE USBi
The USBi has several functions for controlling the target hardware.
The control options are accessed in SigmaStudio by right-clicking
on the USB Interface in the Hardware Configuration tab.
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0
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Figure 15. USBi Control Menu
Figure 12. Multiple Address Operation with SPI
Capture Output Data
Multiple Latch Operation with SPI
This option accesses the Capture Window, which displays a log
of all communication between the PC and the target IC
(see Figure 1
The USBi can support devices on five different SPI latches.
When multiple latches are used, the additional SPI latch signals
from the USBi that are not connected to the ribbon cable need
to be manually wired to the target.
7).
Device Power On/Off
This option switches the line that supplies power to the target
board. By default, the device power is on.
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Device Enable/Disable
For supported ICs, selecting this option switches the device to
low power mode.
Reset USB Interface
This function performs a software reset of the USB driver, and
causes the Cypress USB microcontroller to reload its firmware.
Figure 13. Multiple Latch Operation with SPI
The locations of extended SPI latch signals are shown in Figure 14.
0x01
0x03
0x02 0x04
0x05
Q1
R12
R11
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Figure 14. Extended SPI Latch Signal Pinout (Bottom View of Board)