Hw Processor (Hwp) And Sound Output; Overview - Epson S1C31D50 Technical Manual

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:
• Multi-channel mixer
• 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.
• 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.
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.
Item
Sound Play function EOV play
Sound channel
Voice playback speed
Sound output circuit
Gapless play
Buzzer output
Memory Check function
S1C31D50/D51 TECHNICAL MANUAL
(Rev. 2.00)
16/24/32/40 kbps
* See Table 21.1.1.
Table 21.1.1 HWP Channel Configuration of S1C31D50/D51
(e.g. can play voice on channel 0 and background music on channel 1)
Seiko Epson Corporation

21 HW Processor (HWP) and Sound Output

S1C31D50
Sampling frequency: 15.625 kHz
Bitrate:
2 channels
75% to 125%, 5% steps (channel 0 only)
SDAC
Not available
Not available Available (T16B Ch.0 TOUT only)
Available
There is no difference depending in the packages.
* See Table 21.1.1.
* See Table 21.1.1.
S1C31D51
16/24/32/40 kbps
SDAC or T16B Ch.0 TOUT
Available
Available
21-1