To test a chip output, the wired Pico input is read twice, once with input_pulldown and once with input_pulldown to really detect driven High and Low as well as three-state, high impedance Z. Furthermore, when inputs, addresses or control lines do not matter, the testing goes thru all their permutations to make sure that their state and transition do really not matter. This intense testing is not visible in the output, especially for the last block that does multi-writes and multi-reads. Looking at the nested loops in the code makes though clear that it is not just a write and then a read for each of the 8 bits, but a got 1300 - thirteen hundred tests... (may be I'm paranoid... because all chips I got passed w/ flying colors).
// MC14599_8B_ADDR_LATCH.js
// 20230327ao
//
// Using pico to test NOS MC14599B 8-Bit Addressable Latches
//
var lon = true; // false; // true; // logging is on
function log() { if (lon) { console.log.apply(console,arguments); } }
// wire connections
// ic - pico
var CQ0=A0, CQ1=A1, CQ2=A2, CQ3=A3, CQ4=A4, CQ5=A5, CQ6=A6, CQ7=A7
, CW_R=B1, CE=B7, CWDS=B8, CRST=B9
, CA0=B3, CA1=B4, CA2=B5
, CD=B6
, CQ = [CQ7, CQ6, CQ5, CQ4, CQ3, CQ2, CQ1, CQ0]
, CA = [CA2, CA1, CA0]
;
function setPinModes() {
// driving the chip controls
pinMode(CW_R,"output");
pinMode(CE ,"output");
pinMode(CWDS,"output");
pinMode(CRST,"output");
// driving the bit latch address lines
pinMode(CA0,"output");
pinMode(CA1,"output");
pinMode(CA2,"output");
// reading the 8B latches
pinMode(CQ0,"input");
pinMode(CQ1,"input");
pinMode(CQ2,"input");
pinMode(CQ3,"input");
pinMode(CQ4,"input");
pinMode(CQ5,"input");
pinMode(CQ6,"input");
pinMode(CQ7,"input");
// reading / writing the chip data (preset)
pinMode(CD,"input");
}
function hex(v) { return ((v>15) ?
hex(v>>4) : "")+"0123456789ABCDEF".charAt(v&15); } // hex...
function hep(v,ds) { // hex, digits (w/ blank padding up to ds)
return (" "+hex(v)).substr(-ds); }
function lep(v,ds) { // hex, digits (w/ 0 padded up to ds)
return ("00000000"+hex(v)).substr(-ds); }
var tMax = 1 // test repetitions
, tCnt = 0
, passed, somePassed, someFailed
;
var tester =
{ test: function() { // tester object (tool)
log(++tCnt);
this.tResetLatch();
this.tResetData();
this.tChipDisableLatch(true); // onReset
this.tChipDisableData( true); // onReset
this.tChipDisableLatch(false); // w all 0 then 1 - tests all to 1
this.tChipDisableData( false); // w all 0 then 1 - tests all to 1
this.tChipDisableLatch(false); // w all 0 then 1 - tests all to 0
this.tChipDisableData( false); // w all 0 then 1 - tests all to 0
this.tWrite01010();
this.tWriteRead01010();
}
// test reset for latch
// - expects nothing
// - leaves -+CE, -+W_R, +WDS, -+AX(3), -+RST
, tResetLatch: function() {
log("\ntResetLatch","<=====");
var td = "tResetLatch"
, ps=[CE,CW_R,CWDS,CA2,CA1,CA0], px, v, r, t
, p=true, passedCnt=0; failedCnt=0;
this.dIPM(); // data input to avoid any contention
CRST.set();
t = 0;
for (v = 0; v <= 1; v++) {
this.lIPM(v);
for (px = 0; px <= 0x3F; px++) {
digitalWrite(ps,px);
if ((r = digitalRead(CQ)) !== t) { // 0x00
log(td,"FAILED",v,hep(px,2),": 00",lep(r,2));
p = false; failedCnt++;
} else {
passedCnt++;
}
} }
if (p) {
log("-- "+td+" ok");
} else {
log("-- "+td+": passed =",passedCnt,", FAILED =",failedCnt);
}
passed &= p;
digitalWrite(ps,0b001000);
CRST.reset();
}
// test reset for data
// - expects nothing
// - leaves -+CE, -+W_R, +WDS, -+AX(3), -+RST
, tResetData: function() {
log("\ntResetData","<=====");
var td = "tResetData"
, ps=[CE,CW_R,CWDS,CA2,CA1,CA0], px, v, w, r, t
, p=true, passedCnt=0; failedCnt=0;
this.dIPM(); // data input to avoid any contention
CRST.set();
for (v = 0; v <= 1; v++) {
this.lIPM(v); t = v * 0xFF;
for (px = 0; px <= 0x3F; px++) {
for (w = 0; w <= 1; w++) {
this.dIPM(w); t = w;
if ((r = digitalRead(CD)) !== t) { // high imp Z
log(td,"FAILED",v,hep(px,2),":",t,r);
p = false; failedCnt++;
} else {
passedCnt++;
}
}
} }
if (p) {
log("-- "+td+" ok");
} else {
log("-- "+td+": passed =",passedCnt,", FAILED =",failedCnt);
}
passed &= p;
digitalWrite(ps,0b001000);
CRST.reset();
}
// test chip -+enable (disable) for latch
// - expects nothing when w/ rst, otherwis -+CE, -+W_R, +WDS, -+RST
// - leaves -+CE, -+W_R, +WDS, -+AX(3), -+RST conditional use
, tChipDisableLatch: function(withRst) {
log("\ntChipDisableLatch",(withRst)?" WITH ":"WITHOUT","RST","<=====");
var td = "tChipDisableLatch"+((withRst)?"AftReset":"InGeneral")
, ps=[CW_R,CWDS,CA2,CA1,CA0], px, u, v, r, t, tt
, p=true, passedCnt=0; failedCnt=0;
this.dIPM(); // data input to avoid any contention
if (withRst) CRST.set();
CE.reset(); // -+CE disable
if (withRst) CRST.reset();
for (u = 0; u <= 1; u++) {
if ( ! withRst || u === 0) {
t = u * 0xFF; tt = ": " + lep(t,2);
if ( ! withRst) this.allOut(u);
for (v = 0; v <= 1; v++) {
this.lIPM(v);
for (px = 0; px <= 0x2F; px++) {
digitalWrite(ps,px);
if ((r = digitalRead(CQ)) !== t) { // high imp Z
log(td," FAILED",u,v,hep(px,2),tt,lep(r,2));
p = false; failedCnt++;
} else {
passedCnt++;
} } } } }
if (p) {
log("-- "+td+" ok");
} else {
log("-- "+td+": passed =",passedCnt,", FAILED =",failedCnt);
}
passed &= p;
digitalWrite(ps,0b001000);
}
// test chip -enable (disable) for data
// - expects nothing
// - leaves -+CE, -+W_R, +WDS, -+AX(3), -+RST conditional use
, tChipDisableData: function(withRst) {
log("\ntChipDisableData",(withRst)?" WITH ":"WITHOUT","RST","<=====");
var td = "tChipDisableData"+((withRst)?"AftReset":"InGeneral")
, ps=[CW_R,CWDS,CA2,CA1,CA0], px, v, w, r, t
, p=true, passedCnt=0; failedCnt=0;
this.dIPM(); // data input to avoid any contention
if (withRst) CRST.set();
CE.reset(); // -+CE disable
if (withRst) CRST.reset();
for (u = 0; u <= 1; u++) {
if ( ! withRst || u === 0) {
if ( ! withRst) this.allOut(u);
for (v = 0; v <= 1; v++) {
this.lIPM(v);
for (px = 0; px <= 0x2F; px++) {
for (w = 0; w <= 1; w++) {
this.dIPM(w); t = w;
if ((r = digitalRead(CD)) !== w) {
log(td," FAILED",v,hep(px,2),w,r);
p = false; passedCnt++;
} else {
passedCnt++;
} } } } } }
if (p) {
log("-- "+td+" ok");
} else {
log("-- "+td+": passed =",passedCnt,", FAILED =",failedCnt);
}
passed &= p;
digitalWrite(ps,0b001000);
}
// test write individual outputs
// - expects -+CE, -+W_R, +WDS, -+AX(3), -+RST
// - leaves -+CE, -+W_R, +WDS, -+AX(3), -+RST not in use
, tWrite01010() {
log("\ntWrite01010","<=====");
var td = "tWrite01010"
, vs = [0,1,0,1,0]
, ps=[CW_R,CWDS,CA2,CA1,CA0]
, addr, t = 1, w, vx, v, r
, p=true, passedCnt=0; failedCnt=0;
this.allOut(0); passed &= this.validateQX(td,"setup QX=00",0);
for (addr = 0; addr <=7; addr++) {
for (vx = 0; vx <= 4; vx++) {
v = vs[vx]; w = v * t;
this.write(addr,v);
if ( ! this.validateQX(td,"write",w)) {
log(td,"FAILED",addr,v,":",lep(w,2),lep(digitalRead(CQ),2));
p = false; failedCnt++;
} else {
passedCnt++;
}
}
t = t<<1;
}
if (p) {
log("-- "+td+" ok");
} else {
log("-- "+td+": passed =",passedCnt,", FAILED =",failedCnt);
}
passed &= p;
digitalWrite(ps,0b001000);
}
// test write individual outputs
// - expects -+CE, -+W_R, +WDS, -+AX(3), -+RST
// - leaves -+CE, -+W_R, +WDS, -+AX(3), -+RST not in use
, tWriteRead01010() {
log("\ntWriteRead01010","<=====");
var td = "tWriteRead01010"
, vs = [0,1,0,1,0]
, ps=[CW_R,CWDS,CA2,CA1,CA0]
, wddr, rddr, t = 1, w, vx, v, r
, p=true, passedCnt=0; failedCnt=0;
this.allOut(0); passed &= this.validateQX(td,"setup QX=00",0);
for (wddr = 0; wddr <=7; wddr++) {
for (vx = 0; vx <= 4; vx++) {
v = vs[vx]; w = v * t;
this.write(wddr,v);
if ( ! this.validateQX(td,"write",w)) {
log(td,"write FAILED, skip read",wddr,v,":",lep(w,2),lep(digitalRead(CQ),2));
p = false; failedCnt += 8;
} else {
// log(td,"write OK, do read",wddr,v,":",lep(w,2),lep(digitalRead(CQ),2));
for (rddr = 0; rddr <= 7; rddr++) {
if (rddr === wddr) { // exp v
r = this.read(rddr,w = v);
} else {
r = this.read(rddr,w = 0);
}
if (r !== w) {
log(td,"read FAILED",wddr,rddr,v,":",w,r);
p = false; failedCnt++;
} else {
// log(td,"read OK",wddr,rddr,v,":",t,r);
passedCnt++;
}
}
}
}
t = t<<1;
}
if (p) {
log("-- "+td+" ok");
} else {
log("-- "+td+": passed =",passedCnt,", FAILED =",failedCnt);
}
passed &= p;
digitalWrite(ps,0b001000);
}
// setup latch QX for input w/ pull-up or pull-down
, lIPM: function(falseOrTrue) { // input _pulldown / _pullup
var pull = "input_" + ((falseOrTrue) ? "pullup" : "pulldown");
for (var p=0; p<8; p++) { pinMode(CQ[p],pull); } }
// setup data QD for input w/ pull-up or pull-down
, dIPM: function(falseOrTrue) { // input _pulldown / _pullup
pinMode(CD,"input_" + ((falseOrTrue) ? "pullup" : "pulldown")); }
// setup data QD for input w/ high imp Z
, dIM: function() { pinMode(CD,"input"); }
// setup data QD for output
, dOM: function() { pinMode(CD,"output"); }
// set all latches to value
, allOut(v) {
log("allOut(",v,") <-----");
for (var a=0; a<=7; a++) this.write(a,v);
log("allOut:",v,lep(digitalRead(CQ),2));
}
// write at addr data bit
// expects -+CE, -+W_R, +WDS, -+RST (not used)
// leaves -+CE, -+W_R, +WDS, -+RST
, write(addr,data) {
CWDS.set();
digitalWrite(CA,addr & 7);
CW_R.set();
this.dOM();
digitalWrite(CD,data & 1);
CE.set();
CWDS.reset();
CWDS.set();
this.dIM();
CW_R.reset();
CE.reset();
}
// read at addr data bit (w/ opposite pull when exp !== null - false/true/0/1)
// expects -+CE, -+W_R, +WDS, -+RST (not used)
// leaves -+CE, -+W_R, +WDS, -+RST (uses only +CE)
, read(addr,exp) {
var r;r = (exp === undefined) ? undefined : ! exp;
digitalWrite(CA,addr & 7);
if ((r = (exp === undefined) ? undefined : ! exp) === undefined) {
this.dIM();
} else {
this.dIPM(r);
}
CE.set();
r = digitalRead(CD);
CE.reset();
this.dIM();
return r;
}
// validate QX === t w/ pulldown and pullup
, validateQX: function(td, det, t) {
var p = true;
this.lIPM(0);
if ((r = digitalRead(CQ)) !== t) {
log(td, det, "FAILED", lep(t,2), lep(r,2));
p = false; }
this.lIPM(1);
if ((r = digitalRead(CQ)) !== t) {
log(td, det, "FAILED", lep(t,2), lep(r,2));
p = false; }
return p;
}
}
;
function onInit() {
setPinModes();
somePassed = false; someFailed = false;
var tIId = setInterval(function() {
LED1.reset(); LED2.reset();
passed = true;
tester.test();
if (passed) {
LED2.set(); somePassed = true;
} else {
LED1.set(); someFailed = true;
}
if (tCnt>=tMax) {
clearInterval(tIId);
if (somePassed) { LED2.set(); }
if (someFailed) { LED1.set(); }
}
},750);
}
setTimeout(onInit,999); // dev only; remove before upload for save()
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The test code...
To test a chip output, the wired Pico input is read twice, once with
input_pulldown
and once withinput_pulldown
to really detect driven High and Low as well as three-state, high impedance Z. Furthermore, when inputs, addresses or control lines do not matter, the testing goes thru all their permutations to make sure that their state and transition do really not matter. This intense testing is not visible in the output, especially for the last block that does multi-writes and multi-reads. Looking at the nested loops in the code makes though clear that it is not just a write and then a read for each of the 8 bits, but a got 1300 - thirteen hundred tests... (may be I'm paranoid... because all chips I got passed w/ flying colors).A corresponding ouput: