参数资料
| 型号： | DM300014 |
| 厂商： | Microchip Technology |
| 文件页数： | 40/72页 |
| 文件大小： | 0K |
| 描述： | BOARD DEMO DSPICDEM 1.1 GEN PURP |
| 标准包装： | 1 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页当前第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页第65页第66页第67页第68页第69页第70页第71页第72页
dsPICDEM? 1.1 Development Board User’s Guide
3.4.3
3.4.3.1
Interrupts Used in the Demo
EXTERNAL INTERRUPTS TO MAIN ROUTINE
External interrupts INT1-INT4 are controlled by switches SW1-SW4.
These switches provide selection capabilities for the demo program. The most recent
switch presses are recorded in a variable within the interrupt routines. In the main
routine, the variable is analyzed to determine what action is requested by the recent
switch event.
3.4.3.2
DCI INTERRUPTS AND DTMF
The DCI module interrupts the CPU when all four TXBUF registers have been
transmitted. The DCI is used to send out DTMF tones to the Codec. The tonal
components are stored as sinusoid tables in program memory and accessed using
Program Space Visibility (PSV).
The DCI ISR keeps track of the number of samples sent. The DTMF tones are
transmitted by adhering to International Telecommunication Union (ITU-T)
specifications. For example, the ON time for tones is greater than 40 mS and the OFF
time is less than 23 mS. The actual values are 100 mS of ON time and 15 mS of OFF
time. When playing a pre-recorded sequence of tones, a PAUSE time is added
between successive tones. This time is equal to the ON time of the tone. Also, the high
and low frequency of the DTMF tone are separated by 8 dB. The high frequencies are
reduced in magnitude relative to the low frequencies by 8 dB.
3.4.3.3
UART RECEIVE INTERRUPTS
Single DTMF tones may also be played by entering numeric characters (0-9) on the PC
keyboard during the HyperTerminal session. The UART receives this keyboard
character, and a receiver interrupt communicates this data to the DCI to start a tone
generation process.
3.4.3.4
UART TRANSMIT INTERRUPTS
Every 1.14 seconds, data is transmitted via the UART to the HyperTerminal session
window. Four bytes are loaded at a time in the Transmitter Buffer registers. The term
“data” refers to the following:
?
?
?
?
?
Analog data such as RP1, RP2 and RP3
Temperature sensor data
FFT frequency and bin number of the sampled input sinewave signal
Cycle count information for the FFT, FIR or IIR algorithms
Chosen Filter Type – IIR, FIR or None
3.4.3.5
SPI INTERRUPTS, DIGITAL POT AND THE LCD CONTROLLER
The SPI 2 module is used to perform two functions:
? When the demo code is waiting for the A/D converter to collect 256 samples of
data on pin AN3, the SPI 2 module is used by the Timer1 ISR to transmit
sine-wave samples to the MCP41010 every 125 microseconds at a data rate of
230 kHz.
? When code execution reaches the DSP stage (i.e., filtering, FFT etc.) the SPI 2
module is used to send data to the PIC18F242 LCD controller on the expansion
board at a data rate of 921.6 KHz (F CY /8). The LCD has a 4 row x 20-character
display. All 80 characters are refreshed by the SPI 2 module.
DS70099B-page 36
Advance Information
? 2003 Microchip Technology Inc.
相关PDF资料 |
PDF描述 |
|---|---|
| DM300016 | BOARD DEMO DSPICDEM STARTER |
| DM300017 | BOARD DEMO DSPICDEM STARTER |
| DM300020 | BOARD DEV DSPICDEM MC1 MOTORCTRL |
| DM300021 | MODULE PWR DSPICDEM MC1H HV 3PHS |
| DM300022 | MODULE PWR DSPICDEM MC1L LV 3PHS |
相关代理商/技术参数 |
参数描述 |
|---|---|
| DM300015 | 功能描述:KIT DESIGN W/DM300014 RoHS:否 类别:编程器，开发系统 >> 过时/停产零件编号 系列:- 标准包装:1 系列:* |
| DM300016 | 功能描述:开发板和工具包 - PIC / DSPIC dsPICDEM Starter RoHS:否 制造商:Microchip Technology 产品:Starter Kits 工具用于评估:chipKIT 核心:Uno32 接口类型: 工作电源电压: |
| DM300017 | 功能描述:开发板和工具包 - PIC / DSPIC dsPICDEM 28P Starter RoHS:否 制造商:Microchip Technology 产品:Starter Kits 工具用于评估:chipKIT 核心:Uno32 接口类型: 工作电源电压: |
| DM300017 | 制造商:Microchip Technology Inc 功能描述:Microcontroller Development To |
| DM300018 | 功能描述:开发板和工具包 - PIC / DSPIC dsPICDEM 2 Demo Brd RoHS:否 制造商:Microchip Technology 产品:Starter Kits 工具用于评估:chipKIT 核心:Uno32 接口类型: 工作电源电压: |
发布紧急采购，3分钟左右您将得到回复。