Are you mistaking RefMux and AMUX ?
Looks like the P/N not in datasheet a simple omission. If RefMux placed code
is generated for its API's and definitions, eg, looks like it is a normal accessable
component/module for the 28xxx series of parts.
I concur with Bob, RefMux does not "feed" the column mux, you are thinking of
Dear Bob and Dana,
thank you for your replies, I'm referring to RefMux.
As reported in the datasheet the RefMux can be used to provide "... a method to route external analog inputs directly to the analog output bus" (from the datasheet), by selecting the PMuxOut input.
The attachment "RefMuxPlacement.jpg" report the use of RefMux in a CY8C27443 project where you can see the link between the analog mux output and the RefMux input; if I use the CY8C28623 this link can't be established, maybe it is only a "graphical" issue.
Please let me know your opinion.
RefMuxPlacement.jpg 19.6 K
There is no connection between an input pin of port0 to the RefMux output and analog buf. You only may select from the sources from the list. The connection is as unusable as the clock source selection for a column connected to a ctb (upper row). When you want to route different pins to the output buffer, use a PGA gain 1.0 and make the appropiate connections.
Yes, using the PMUXout input to the RefMux one of 4 pins can be routed
direc tly to the analog output buffer. I also concur that one cannot
"see" the route.
The RefMux User Module switches one of three internal references (AGND, REFLO, or REFHI) to the analog output bus. Additionally, the output of the Continuous Time (CT) block PMux multiplexer can be selected. The RefMux User Module makes use of the TestMux in a CT block. These signals may be routed to a switch capacitor block on the bottom analog row or buffered and routed to an external pin. If used in conjunction with the AMux4 User Module, they form a four input analog multiplexer to route signals from one of four pins to the analog output bus.
Figure 1. RefMux Block Diagram
- Low voltage offset path from PMux to analog output bus
- Provides a method to route internal references (AGND, REFHI, REFLO) to an external pin
- Provides a 4 to 1 analog mux for switch capacitor blocks such as ADCs and filters, if used with the AMux4 User Module
- Signals from PMux through test mux may be rail-to-rail
- Provides a method to route external analog inputs directly to the analog output bus
Be carefull regarding the statement about R-R performance. That is true until you pass
thru the output buffer, then a combination of its CM input range and output CM range
destroy all R-R performance.
Dear Dana, thank you for your reply.