This article refers to the address: http://
Abstract: SC-691 is a high quality low data rate speech and background music synthesis chip produced by SENSORY Corporation of the United States. It supports multiple speech synthesis algorithms with data rates as low as 1.0 bps. The SC-691 works in a slave mode and thus does not require a specific development environment. Its biggest feature is that it can play background music while playing voice. It can be used in any product that needs to play voice and music.Key words: SC-791; speech synthesis; synthesizer
1 Overview
SC-691 is a member of the SENSORY company's SC-6xx speech synthesis chip family. It works in slave mode and can receive command and voice compression data from the host and then convert it to voice output. Because it does not require programming knowledge of the SC-6xx, it is the easiest to use product in the SC-6xx family.
The SC-691 is a standard slave synthesizer that works with the main processor and can be used in a variety of voice-related products such as security systems, learning aids, games and toys. Its high quality, low bit rate encryption, easy to interface with host, digital gain control, low power sleep mode, and low voltage operation make it a long time to play voice, a short development cycle, and a slave The ideal device for controlling applications such as peripherals.
   The SC-691 supports multiple speech synthesis algorithms. The data storage capacity used by different algorithms is different. When using the MX synthesis algorithm, the lowest data rate can reach 1.0bps, that is, one second of voice data only occupies one bit space. Users can weigh the relationship between voice quality and data space to meet their performance price requirements.
The biggest feature of the SC-691 is that it can play single-channel FM music in sync with CX/MX voice data, which allows the SC-691 to play background music while speaking in MX/CX format.
2 main characteristics
The SC-691 speech synthesis chip has the following features:
â— Provides unlimited time for voice playback through register extension;
â— Operating speeds up to 12.32 MIPS;
â— Support multiple algorithms, the data rate range: 1.0kbps ~ -3.5kbps at MX and 8kHz sampling frequency; 3.0kbps, 3.7kbps, 4 at CX and 8kHz sampling frequency respectively .5 kbps, 6.2 kbps, 7.7 kbps, and 11.2 bps.
In addition, the device also features ADPCM, single-channel FM synthesis, single-channel FM and CX/MX hybrid modes.
â— Use interrupt driver to transmit voice and commands;
â— With 6 levels of digital gain control;
â— With 4 user configurable I/O ports;
â— has an optional 4-bit or 8-bit data bus;
◠There are three standby modes that reduce power consumption to extend battery life (current less than 10μA in deep sleep mode);
â—The clock is optional, and the user can select the low-cost 1% resistor or the high-precision 32.368kHz crystal oscillator as the system clock according to the situation;
â— Low voltage operation (3V ~ 5.2V), suitable for handheld products;
â—In 4-bit mode, you can stop talking at any time, and can transmit commands while supporting speech to perform certain tasks, which can directly drive 32Ω speakers;
â—Play single channel FM music while playing CX/MX voice data;
â— Available in die and 64-pin LQFP packages.
3-pin function and internal structure
The SC-691 is available in a 36-pin die and a 64-pin LQFP package. Figure 1 shows the pinout diagram of its LQFP package. The function description of each pin is listed in Table 1. Figure 2 is a block diagram of its internal structure.
Table 1 Pin Description of SC-691
| Lead | Pin name | I/O type | Features |
| 39~36 | DATA0~DATA3 | input Output | Data bits 0 to 3 |
| 35 | DATA4 or DATA/COMMAND | input Output | The 4-bit mode is the DATA/COMMAND pin, which is used to indicate whether the command or data is transmitted by the host. 8-bit mode is data bit 4 |
| 3432 | DATA5~DATA7 | input Output | Data bits 5 to 7 (in 8-bit mode) |
| 6 | INRDY | Output | The output signal from the slave to the host. A low level indicates that the SC-691 is ready to receive data or commands. A high level indicates that the SC-691 is busy and the host cannot write any data or commands to it. |
| 5 | OUTRDY | Output | The output signal sent by the slave to the host. Low level indicates that the SC-691 is ready to send commands or data to the host. |
| 43～40 | PD4~PD7 | input Output | General purpose I/O bus |
| 3 | R/W | enter | Input signal from the host. Set it high when the host reads it, and deassert it when writing |
| 4 | STROBE | enter | Input signal from the host. Used in conjunction with the R/W signal in the read and write sequence. In the sequence of read/write operations, the signal is pulled high-low-high |
| 15 | OSCOUT | Output | Impedance oscillator / crystal oscillator output |
| 14 | OSCIN | enter | Impedance oscillator / crystal oscillator input |
| 13 | PLL | Output | Phase-locked loop filter output |
| 11 | SCANIT | enter | Scan port data input |
| 8 | SCANOUT | Output | Scan port data output |
| 10 | SCANCLK | enter | Scan port clock |
| 9 | SYNC | enter | Scan port synchronization |
| 7 | TEST | enter | Test mode |
| 47 | DACP | Output | Digital-to-analog plus output |
| 45 | DACM | Output | Digital-to-analog output |
| 12 | RESET | enter | Reset pin, active low |
| 1,2,31,44,46 | VDD | Processor power supply, rated voltage is 5V | |
| 16,48,49,64 | VSS | Ground |
4 applications
The SC-691 voice and music synthesis chip has a power supply voltage (VDD) ranging from 3 to 5.2V. Its CPU clock f?CPU? range is 64 to 12320 kHz. The load resistance between the DACP and the DACM is the smallest. Should be greater than 32 Ω.
Depending on the width of the communication data bus, the SC-691 has two communication modes: 4-bit mode and 8-bit mode. The bus resources required for the two modes are shown in Table 2.
Table 2 Communication resource allocation table
| Specific bus | SC-691 (4-bit mode) | SC-691 (8-bit mode) |
| Data line bus | 4 | 8 |
| Control line bus | 3 (STROBE, R/W, data/command) | 2 (STROBE, R/W) |
| Status line bus | 2 (INRDY, OUTRDY) | 2 (INRDY, OUTRDY) |
| General purpose I/O port bus | 4 | 4 |
| Command support (when talking) | Yes | bundle |
Figure 3 is a system block diagram of a voice e-book. Among them, the pluggable memory card stores the voice data available to the SC-691. The contents of the e-book can be replaced by replacing the contents of the pluggable memory card. In general, an MMC card can be used.
The master can communicate with the PC through the serial interface to replace the contents of the e-book. The master reads the data in the card and transfers the data to the SC-691 to play it out.
The received voice data (ie, e-book content) signals can be synthesized and played back using the SC-691. The content of the e-book can be displayed by text form using the display module.
The input module is used to control the e-book, such as switching on and off, reading, and the like. In this system, the master communicates with the SC-691 in 4-bit mode.
Usb 2.0 Extend Dock,Usb 2.0 Docking Cable,Usb Extension Cables
USB3.0/2.0 Docking Station Wireless Adapter Co.,Ltd , http://www.chwirelessrouter.com