21 HW Processor (HWP) and Sound Output
S1C31D50/D51 TECHNICAL MANUAL
Seiko Epson Corporation
21-1
(Rev. 2.00)
21 HW Processor (HWP) and Sound
Output
21.1 Overview
HWP is a functional block having the “Sound Play” and “Memory Check” functions. It can work without any
CPU resources by only issuing a command. HWP uses SDAC (S1C31D50/D51) or T16B Ch.0 (S1C31D51) for
sound output. SDAC is a DAC that converts the sound data generated by the HWP into PWM signals and outputs
them to the external audio amplifier. T16B Ch.0 operates similarly, but it does not need an external amplifier. So, a
voice and audio playback function can be realized with a buzzer and a small number of external components in the
S1C31D51. The features of the HWP are listed below.
Sound Play function
• EPSON high quality and high compression algorithm (EOV: EPSON Original Sound Format)
- Sampling Frequency: 15.625 kHz
- Bitrate:
16/24/32/40 kbps
• Multi-channel mixer
*
See Table 21.1.1.
• Voice speed conversion from 75% to 125% in 5% steps (for channel 0)
• A silent period is inserted between phrases. Gapless play can also be selected.
*
See Table 21.1.1.
• Sequential playing of multiple sound files
• External QSPI-Flash* supported for storing sound data
• Either SDAC or T16B Ch.0 TOUT can be selected as the sound output circuit via software.
*
See Table 21.1.1.
Note: T16B Ch.0 cannot be used while the S1C31D51 is outputting sound through the T16B Ch.0
TOUT. Do not use T16B Ch.0 to generate interrupts (refer to Section 17.5) and DMA transfer re-
quests (refer to Section 17.6).
Memory Check function
• Embedded RAM check (read/write check algorithm or March-C algorithm)
• Embedded Flash check (checksum or CRC algorithm)
• External QSPI-Flash* check (checksum or CRC algorithm)
* Supports QSPI Flash memories with XIP (eXecute-In-Place) mode.
Figure 21.1.1 shows the HWP configuration.
Table 21.1.1 HWP Channel Configuration of S1C31D50/D51
Item
S1C31D50
S1C31D51
Sound Play function EOV play
Sampling frequency: 15.625 kHz
Bitrate:
16/24/32/40 kbps
Sound channel
2 channels
(e.g. can play voice on channel 0 and background music on channel 1)
Voice playback speed
75% to 125%, 5% steps (channel 0 only)
Sound output circuit
SDAC
SDAC or T16B Ch.0 TOUT
Gapless play
Not available
Available
Buzzer output
Not available
Available (T16B Ch.0 TOUT only)
Memory Check function
Available
Available
There is no difference depending in the packages.