16 SOUND GENERATOR (SNDA)
S1C17M20/M21/M22/M23/M24/M25
Seiko Epson Corporation
16-1
TECHNICAL MANUAL (Rev. 1.0)
16 Sound Generator (SNDA)
16.1 Overview
SNDA is a sound generator that generates melodies and buzzer signals. The features of the SNDA are listed below.
• Sound output mode is selectable from three types.
1. Normal buzzer mode (for normal buzzer output of which the output duration is controlled via software)
- Output frequency:
Can be set within the range of 512 Hz to 16,384 Hz.
- Duty ratio:
Can be set within the range of 0% to 100%.
2. One-shot buzzer mode (for short buzzer output such as a clicking sound)
- Output frequency:
Can be set within the range of 512 Hz to 16,384 Hz.
- Duty ratio:
Can be set within the range of 0% to 100%.
- One-shot output duration: Can be set within the range of 15.6 ms to 250 ms. (16 types)
3. Melody mode (for playing single note melody)
- Pitch:
Can be set within the range of 128 Hz to 16,384 Hz.
(Scale: 3 octave from C3 to C6 with reference to A4 = 443 Hz)
- Duration:
Can be set within the range of half note/rest to thirty-second note/rest. (7 types)
- Tempo:
Can be set within the range of 30 to 480. (16 types)
- Other:
Tie and slur can be specified.
• A piezoelectric buzzer can be driven with the inverted and non-inverted output pins.
• Can control the non-inverted output pin status while sound stops.
Figure 16.1.1 shows the SNDA configuration.
SNDA
Interrupt control
circuit
EMIE
SINV
SBSY
SSTP
EDIE
EMIF
EDIF
CLKSRC[1:0]
CLKDIV[2:0]
Sound generation
circuit
Output control circuit
Sound buffer
(SNDDAT register)
Sound register
Clock generator
Interrupt
controller
DBRUN
MODEN
CLK_SNDA
MOSEL[1:0]
STIM[3:0]
BZOUT
#BZOUT
Inter
nal data
bu
s
Figure 16.1.1 SNDA Configuration