SP0256 Measured Timings

Here are some measured timings for the SP0256-AL2 speech chip. Mainly here to confirm and understand how it works. All timings were measured by gerald, on a Amstrad SSA-1 with 3.12MHz ceramic resonator.

PWM Output

Allophone Lengths

This table shows the allophone lengths in milliseconds.

• spec = Timings from original datasheets (these values are totally wrong)
• calc = Timings calculated from pitch/repeat values in the -AL2 ROM
• min/avg/max = Timings measured on real hardware (Amstrad SSA-1)

The min/avg/max values are slightly higher than the calculated values. This is probably because the SP0256 executes "NOPs" with repeat=1 while in standby mode, and refuses to start a new allophone until it has finished the "NOP".

num name      spec   calc     min     avg     max
00  PA1       10.0    6.4    6.66   10.05   12.80
01  PA2       30.0   25.6   26.71   31.33   32.37
02  PA3       50.0   44.8   46.05   50.12   51.39
03  PA4      100.0   96.0   97.81  101.72  103.24
04  PA5      200.0  198.4  200.50  204.11  206.69
05  /OY/     420.0  291.2  293.06  297.24  299.12
06  /AY/     260.0  172.9  174.81  175.98  176.96
07  /EH/      70.0   54.6   56.32   57.05   57.94
08  /KK3/    120.0   76.8   78.82   79.89   81.05
09  /PP/     210.0  147.2  148.91  153.20  155.04
0A  /JH/     140.0   98.4   99.15  103.24  105.45
0B  /NN1/    140.0  172.9  174.89  175.81  176.92
0C  /IH/      70.0   45.5   46.80   47.73   48.38
0D  /TT2/    140.0   96.0   98.85   99.47  100.29
0E  /RR1/    170.0  127.4  128.37  132.63  134.44
0F  /AX/      70.0   54.6   55.55   57.01   57.97
10  /MM/     180.0  182.0  184.14  185.08  186.15
11  /TT1/    100.0   76.8   78.47   79.92   80.93
12  /DH1/    290.0  136.5  137.33  141.89  143.54
13  /IY/     250.0  172.9  174.31  175.74  176.46
14  /EY/     280.0  200.2  201.75  202.85  203.69
15  /DD1/     70.0   45.5   46.95   48.12   49.14
16  /UW1/    100.0   63.7   65.20   66.21   66.78
17  /AO/     100.0   72.8   74.09   75.46   76.50
18  /AA/     100.0   63.7   64.51   65.72   67.49
19  /YY2/    180.0  127.4  128.82  129.93  131.25
1A  /AE/     120.0   81.9   83.35   84.44   85.51
1B  /HH1/    130.0   89.6   91.78   92.79   93.78
1C  /BB1/     80.0   36.4   37.44   41.30   43.08
1D  /TH/     180.0  128.0  130.04  130.96  131.91
1E  /UH/     100.0   72.8   73.53   77.48   79.34
1F  /UW2/    260.0  172.9  174.95  175.91  176.66
20  /AW/     370.0  254.8  256.68  258.09  259.14
21  /DD2/    160.0   72.1   73.42   74.94   76.17
22  /GG3/    140.0  110.5  111.86  113.73  114.78
23  /VV/     190.0  127.4  128.55  130.10  131.48
24  /GG1/     80.0   72.1   73.55   75.05   75.85
25  /SH/     160.0  198.4  201.15  202.43  203.59
26  /ZH/     190.0  134.1  135.23  139.72  141.61
27  /RR2/    120.0   81.9   82.45   87.02   88.53
28  /FF/     150.0  108.8  111.12  112.07  113.32
29  /KK2/    190.0  134.4  136.08  140.64  142.21
2A  /KK1/    160.0  115.2  116.63  121.24  122.82
2B  /ZZ/     210.0  148.6  149.79  153.20  155.85
2C  /NG/     220.0  200.2  202.19  203.01  204.00
2D  /LL/     110.0   81.9   82.75   84.16   85.52
2E  /WW/     180.0  145.6  147.85  148.41  149.52
2F  /XR/     360.0  245.7  247.67  248.61  249.59
30  /WH/     200.0  145.2  147.29  148.30  149.80
31  /YY1/    130.0   91.0   92.79   94.04   94.87
32  /CH/     190.0  147.2  149.15  150.62  151.77
33  /ER1/    160.0  109.2  109.87  114.27  116.10
34  /ER2/    300.0  209.3  211.77  212.71  213.70
35  /OW/     240.0  172.9  174.74  176.24  177.05
36  /DH2/    240.0  182.0  183.81  184.58  185.83
37  /SS/      90.0   64.0   65.48   66.66   67.66
38  /NN2/    190.0  136.5  141.65  142.48  143.68
39  /HH2/    180.0  126.0  128.30  128.99  130.16
3A  /OR/     330.0  236.6  238.56  240.04  241.20
3B  /AR/     290.0  200.2  202.69  203.70  204.72
3C  /YR/     350.0  245.7  247.68  249.01  250.33
3D  /GG2/     40.0   69.4   71.15   71.96   73.17
3E  /EL/     190.0  136.5  138.22  139.21  140.52
3F  /BB2/     50.0   50.2   51.92   53.17   54.10