Ollie Milton
Driver for a CD22M3494 cross point switcher
Library description
The CD22M3494 is a 16x8 crosspoint switch matrix, it can be used in any configuration i.e. 16 ins' 8 outs' or 16 outs' and 8 ins'. Control of the chip is pretty simple there are two parallel address buses a 4 byte address controls the X axis (16 IO pins) and a 3 byte address controls the Y axis (8 IO pins). A data bus says whether to open or close the switch and a 'strobe' bus actually performs the switch. This library provides a simple interface to control the CD22M3494 and provides a mechanism to associate source and destinations in pairs and switch the pairs via their names.
Diff: CD22M3494.h
- Revision:
- 0:5ef90cd25c10
- Child:
- 1:bc9ca1d1d7a6
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/CD22M3494.h Tue Sep 03 12:49:43 2013 +0000
@@ -0,0 +1,132 @@
+#ifndef CD22M3494_H
+#define CD22M3494_H
+
+#include <mbed.h>
+/*
+X ADDRESS
+AX3 AX2 AX1 AX0 X SWITCH
+ 0 0 0 0 X0
+ 0 0 0 1 X1
+ 0 0 1 0 X2
+ 0 0 1 1 X3
+ 0 1 0 0 X4
+ 0 1 0 1 X5
+ 0 1 1 0 X12
+ 0 1 1 1 X13
+ 1 0 0 0 X6
+ 1 0 0 1 X7
+ 1 0 1 0 X8
+ 1 0 1 1 X9
+ 1 1 0 0 X10
+ 1 1 0 1 X11
+ 1 1 1 0 X14
+ 1 1 1 1 X15
+*/
+
+#define X0 0x00
+#define X1 0x01
+#define X2 0x02
+#define X3 0x03
+#define X4 0x04
+#define X5 0x05
+#define X12 0x06
+#define X13 0x07
+#define X6 0x08
+#define X7 0x09
+#define X8 0x0A
+#define X9 0x0B
+#define X10 0x0C
+#define X11 0x0D
+#define X14 0x0E
+#define X15 0x0F
+
+/*
+Y ADDRESS
+AY2 AY1 AY0 Y SWITCH
+ 0 0 0 Y0
+ 0 0 1 Y1
+ 0 1 0 Y2
+ 0 1 1 Y3
+ 1 0 0 Y4
+ 1 0 1 Y5
+ 1 1 0 Y6
+ 1 1 1 Y7
+*/
+
+#define Y0 0x0
+#define Y1 0x1
+#define Y2 0x2
+#define Y3 0x3
+#define Y4 0x4
+#define Y5 0x5
+#define Y6 0x6
+#define Y7 0x7
+
+#define MAX_X 0x0F
+#define MAX_Y 0x7
+
+class CD22M3494 {
+
+public:
+
+ CD22M3494(PinName x0, PinName x1, PinName x2, PinName x3, PinName y0, PinName y1, PinName y2, PinName d, PinName str, PinName rs) {
+ xbus = new BusOut(x0, x1, x2, x3);
+ ybus = new BusOut(y0, y1, y2);
+ data = new DigitalOut(d);
+ strobe = new DigitalOut(str);
+ reset = new DigitalOut(rs);
+ data->write(0);
+ strobe->write(0);
+ reset->write(0);
+ }
+
+ ~CD22M3494() {
+ delete xbus;
+ delete ybus;
+ delete data;
+ delete strobe;
+ delete reset;
+ }
+
+ bool crossPointConnect(unsigned short x, unsigned short y) {
+ if (x <= MAX_X && y <= MAX_Y) {
+ data->write(1);
+ xbus->write(x);
+ ybus->write(y);
+ // let the data busses settle before setting strobe high
+ wait_us(2);
+ strobe->write(1);
+ // strobe must be high for at least 20 ns
+ wait_us(1);
+ strobe->write(0);
+ return true;
+ }
+ return false;
+ }
+
+ bool crossPointDisconnect(unsigned short x, unsigned short y) {
+ if (x <= MAX_X && y <= MAX_Y) {
+ data->write(0);
+ xbus->write(x);
+ ybus->write(y);
+ // let the data busses settle before setting strobe high
+ wait_us(2);
+ strobe->write(1);
+ // strobe must be high for at least 20 ns
+ wait_us(1);
+ strobe->write(0);
+ return true;
+ }
+ return false;
+ }
+
+private:
+ BusOut* xbus;
+ BusOut* ybus;
+ DigitalOut* data;
+ DigitalOut* strobe;
+ DigitalOut* reset;
+};
+
+
+#endif
\ No newline at end of file