User's Manual
— 8 —
Digital Signal Processor (HG51A115A01FD)
Upon receipt of note numbers and their velocities, the DSP reads sound and velocity data from the sound
source ROM in accordance with the selected tone; the DSP can read rhythm data simultaneously when a
rythm pattern is selected. Then it provides 16-bit serial signals containing data of the melody, chord, bass,
and percussion to the DAC. The DSP also adds the selected effect to the sound data using a 256k-bit
RAM.
The following table shows the pin functions of the DSP.
Pin No. Terminal In/Out Function
1 ~ 8 CD0 ~ CD7 In/Out  Data bus
9, 10  Not used.
11 GND7 In  Ground (0V) source
12 CK16 Out  16.384MHz clock output 
13 VCC6 In  +5V source 
14 CK0 In  Clock input. Connected to terminal CK16.
15 TCKB  Not used.
16 VCC1 In  +5V source
17 GND1 In  Ground (0V) source
18, 19 XT0, XT1 In/Out  16.384MHz clock input/output. Connected to a crystal oscillator.
20 SGL In  System control terminal. Single chip system: Open
21 CCSB In  Chip select signal input
22 ~ 25 CA0 ~ CA3 In  Addess bus
26 CE0 In  Not used. Connected to ground.
27 CWRB In  Write enable signal
28 CRDB In  Read enable signal
29 ~ 32  Not used.
33 RESB In  Reset signal input
34 TESB In  Not used. Connected to +5V. 
35 ~ 39  Not used.
40 ~ 49
52 ~ 57
RD0 ~ RD15 In  Data bus for the sound source ROM
58 RA23 Out  Not used.
59 RA22 Out  Chip select signal for the sound source ROM
60, 61 RA20, RA21 Out  Not used.
62 ~ 73
75 ~ 82
RA0 ~ RA19 Out  Data bus for the sound source ROM
74 GND5 In  Ground (0V) source
83 WOK2 Out  Word clock output. Not used.
84 VCC3 In  +5V source
85 GND3 In  Ground (0V) source
86 WOK1 Out  Word clock for the DAC
87 SOLM Out  Serial data output. Not used.
88 SOLP Out  Serial data output for the DAC
89 BOK Out  Bit clock output for the DAC
90 ~ 92  Not used.










