NCR 5953 manual Configurable Key Click Tone, USB DynaKey Tone Frequencies

4-8 Chapter 4: Programming

Configurable Key Click Tone

The FPGA has the ability to sound a short chirp whenever a key is pressed, providing auditory feedback to an operator of the keyboard. This auditory feedback is optional. The FPGA may be configured to make the sound or not to make the sound, depending on the particular application.

USB DynaKey Tone Frequencies

The frequency is transmitted to the FPGA as a Note Number. Note numbers are equivalent to specific frequencies. The note number sent to the FPGA is selected by rounding the requested frequency to the nearest frequency number given by the table of Note Numbers (N) and Frequencies (freq) listed in the following table.

Table 2: Note Numbers and Frequencies

Note	N	freq	N	freq	N	freq	N	freq	N	freq	N	freq
A	0	28	24	110	48	440	72	1760	96	7040	120	28160
Bb	1	29	25	117	49	466	73	1865	97	7459	121	29834
B	2	31	26	123	50	494	74	1976	98	7902	122	31609
C	3	33	27	131	51	523	75	2093	99	8372	123	33488
Db	4	35	28	139	52	554	76	2217	100	8870	124	35479
D	5	37	29	147	53	587	77	2349	101	9397	125	37589
Eb	6	39	30	156	54	622	78	2489	102	9956	126	39824
E	7	41	31	165	55	659	79	2637	103	10548	127	42192
F	8	44	32	175	56	698	80	2794	104	11175
Gb	9	46	33	185	57	740	81	2960	105	11840
G	10	49	34	196	58	784	82	3136	106	12544
Ab	11	52	35	208	59	831	83	3322	107	13290
A	12	55	36	220	60	880	84	3520	108	14080
Bb	13	58	37	233	61	932	85	3729	109	14917