ADSP-21368 SHARC Processor Hardware Reference 14-23
System Design
System Design Considerations
It is important that an external 10 kΩ pull-up resistor is placed on the
RESETOUT/CLKOUT/RUNRSTOUT pin if it is intended to be used as an input for
initiating a running reset on the ADSP-2137x processor as shown in
Figure 14-4. Also, it is extremely important to ensure that an external
device, such as a micro controller, does not drive this signal during or after
coming out of a power-on or hard-reset.
Figure 14-4 shows the active state of the pin during and after RESET. The
ADSP-2137x processor is actively driving this pin as an output.
If the system uses an external host or micro controller to control running
reset, ensure that the external device waits until the ADSP-2137x proces-
sor driver has been internally disabled (by writing to the RUNRSTCTL
register) before actively driving this signal at
RESET. Connect the CLKOUT
pin to an open-drain pin on the host side, or use an external three-state
buffer.
Figure 14-4. RESETOUT/CLKOUT Pin Muxed with RUNRSTIN
PAD
DRIVER
CLKOUT/
RESETOUT
RUNRSTIN
+Vdd
10 k
Ω
Ensure that host
processor has an
open drain output
and is not actively
driving this pin
during or after
RESET
ADSP-2137x
To Next Page
Loading...
Need help?
General
