AD9734_06 Datasheet, PDF (46/72 Pages) Analog Devices – 10-/12-/14-Bit, 1200 MSPS DACS

AD9734/AD9735/AD9736
GENERATING EXPECTED SIGNATURES
The following MATLAB code duplicates the internal logic of
the AD973x. To use it, save this code in a file called bist.m.
--- begin bist.m ---
function [ ret1 , ret2] = bist(vec)
ret1 = bist1(vec(1:2:length(vec)-1));
ret2 = bist1(vec(2:2:length(vec)));
function ret = bist1(v)
sum = zeros(1,32);
for i = 1 :length(v)
if v(i) ~= 0
su(1) = ~xor(sum(32) ,bitget(v(i),1));
su(2) = ~xor(sum(1) ,bitget(v(i),2));
su(3) = ~xor(sum(2) ,bitget(v(i),3));
su(4) = ~xor(sum(3) ,bitget(v(i),4));
su(5) = ~xor(sum(4) ,bitget(v(i),5));
su(6) = ~xor(sum(5) ,bitget(v(i),6));
su(7) = ~xor(sum(6) ,bitget(v(i),7));
su(8) = ~xor(sum(7) ,bitget(v(i),8));
su(9) = ~xor(sum(8) ,bitget(v(i),9));
su(10) = ~xor(sum(9) ,bitget(v(i),10));
su(11) = ~xor(sum(10) ,bitget(v(i),11));
su(12) = ~xor(sum(11) ,bitget(v(i),12));
su(13) = ~xor(sum(12) ,bitget(v(i),13));
su(14) = ~xor(sum(13) ,bitget(v(i),14));
su(15) = sum(14); su(16) = sum(15);
su(17) = sum(16); su(18) = sum(17);
su(19) = sum(18); su(20) = sum(19);
su(21) = sum(20); su(22) = sum(21);
su(23) = sum(22); su(24) = sum(23);
su(25) = sum(24); su(26) = sum(25);
su(27) = sum(26); su(28) = sum(27);
su(29) = sum(28); su(30) = sum(29);
su(31) = sum(30); su(32) = sum(31);
sum = su;
end
end % for ret = dec2hex( 2.^[0:31]× sum',8);
--- end bist.m ---
To generate the expected BIST signatures, follow this procedure:
1. Start MATLAB and type the following at the command
prompt:
t = round(randn(1,100) × 2¹³/8+2¹³) ;
[ b1 b2 ] = bist(t)
The first statement creates a random vector of 14-bit
words, with a length of 100.
2. Set t equal to any desired vector, or take this random vector
and input it to the AD973x.
3. Alter the command randn(1,100) to change the vector
length as desired.
4. Type b1 at the command line to see the calculated
signature for the LVDS BIST, Phase 1.
5. Type b2 to see the value for LVDS BIST, Phase 2.
The values returned for b1 and b2 each are 32-bit hex values.
They correspond to Reg. 18, Reg. 19, Reg. 20, and Reg. 21,
where b1 is the value read for SEL<1:0> = 0, 0 (see Table 17)
and b2 is the value read for SEL<1:0> = 0, 1.
When the DAC is in 1× mode, the signature at SYNC BIST,
Phase 1 should equal the signature at LVDS BIST, Phase 1. The
same is true for Phase 2.
Rev. A | Page 46 of 72