Simulate Memory Management

Simulate ISR/IST

Program Touch

Program LCD

PCMCIA

GPIO

I2C

Embedded System Flash容量大及使用空間少時，掛載時間長

如果使用JFFS2 file system，
JFFS2 mount時需掃描整個文件系統，導致速度降低。
文件系統接近滿時，因garbage collection問題也會導致速度降低。

YAFFS2
提供了損耗平衡和掉電保護機制，可以有效地避免意外掉電對文件系統一致性和完整性

YAFFS2

YAFFS意為「Yet Another Flash File System」，是目前唯一一個專門為NAND Flash設計的文件系統。它採用了類日誌結構，結合NAND Flash的特點，提供了損耗平衡和掉電保護機制，可以有效地避免意外掉電對文件系統一致性和完

原文網址：https://read01.com/oOLjnD.html

YAFFS2

YAFFS意為「Yet Another Flash File System」，是目前唯一一個專門為NAND Flash設計的文件系統。它採用了類日誌結構，結合NAND Flash的特點，提供了損耗平衡和掉電保護機制，可以有效地避免意外掉電對文件系統一致性和完

原文網址：https://read01.com/oOLjnD.html

YAFFS2

YAFFS意為「Yet Another Flash File System」，是目前唯一一個專門為NAND Flash設計的文件系統。它採用了類日誌結構，結合NAND Flash的特點，提供了損耗平衡和掉電保護機制，可以有效地避免意外掉電對文件系統一致性和完

原文網址：https://read01.com/oOLjnD.html

YAFFS2

YAFFS意為「Yet Another Flash File System」，是目前唯一一個專門為NAND Flash設計的文件系統。它採用了類日誌結構，結合NAND Flash的特點，提供了損耗平衡和掉電保護機制，可以有效地避免意外掉電對文件系統一致性和完

原文網址：https://read01.com/oOLjnD.html

DOCSIS & MoCA

DOCSIS: Data Over Cable Service Interface Specification
MoCA: Multimedia over Coax

使用WPS Pin Code

使用WPS Pin code時，需注意其規則~

需符合下面的checksum
pin += 3 * ((Pincode / 10000000) % 10);
pin += 1 * ((Pincode / 1000000) % 10);
pin += 3 * ((Pincode / 100000) % 10); 

pin += 1 * ((Pincode / 10000) % 10); 

pin += 3 * ((Pincode / 1000) % 10); 

pin += 1 * ((Pincode / 100) % 10); 

pin += 3 * ((Pincode / 10) % 10); 

pin += 1 * ((Pincode / 1) % 10);
最後pin % 10需等於0

WiFi and LAN catch package tools

Sniffer, Wireshare, EtherPeek and Omnipeek

AP Router最大可支援幾個client連線

1. 一個SSID可支援255個IP
2. 受限於RAM & Buffer size
3. 良好的連線品質，上網所需的頻寬(1~2Mbps)

DAB是什麼？

 Digital Audio Broadcasting，數位聲音廣播

Modem Commands

Modem Commands

什麼是Portable Media Center

Portable Media Centers is like Media to go。

  Portable Media Centers put all of your favorite video, music, and pictures at your fingertips wherever you are. Take digital entertainment from your PC with you on the go, including recorded TV shows, downloaded videos, home movies, music, and photos. With Windows Mobile™ software featuring an easy-to-use, familiar Windows Media Center Edition interface, Portable Media Centers let you enjoy immediate access to all of your favorite entertainment - anytime, anywhere.

參考WiKi

什麼是ECMA

ECMA是指國際標準規範組織
參考WiKi

USB3.0 Speed

Low-speed:   1.5Mbps
Full-speed:    12Mbps
High-speed:   480Mbps
Super-speed: 5Gbps

Audio Codec I2S Clock

希望設定Sample Rate為48KHz,
MCLK: 24.576MHz,
選擇MCLK為Main I2S SYSCLK,
設定Main I2S SYSCLK為256Fs = 256*48KHz = 12.288MHz.
由於MCLK是24.576, 所以設定I2S Pre Div為2, 讓Main I2S SYSCLK = 24.576MHz/2 = 12.288MHz.
設定Audio為16bits, BCLK = 32Fs = 32*48KHz = 1.536MHz
MCLK: 24.576MHz
BCLK: 1.536MHz
LRCK: 48KHz
播放1KHz, 0db, wav檔, bit rate = 1536Kbps = 2*16bits*48KHz (Stereo)

RIFF Type Chunk
5249 4646 = 0x52, 0x49, 0x46, 0x46 = RIFF = Chunk ID
24C8 AF00 = 0xAFC824 = 11520036 = 10M = Chunk Data Size = File Size - 8
5741 5645 = 0x57, 0x41, 0x56, 0x45 = WAVE = RIFF Type
WAVE File Chunk
666D 7420 = 0x66, 0x6D, 0x74, 0x20 = fmt = Chunk ID
1000 0000 = 0x10 = Chunk Data Size
0100 = 0x1 = Compression Code = PCM/uncompressed
0200 = 0x2 = Number of Channels = Stereo
80BB 0000 = 0xBB80 = 48K = Sample Rate
00EE 0200 = 0x2EE00 = 192K = Average bytes per second = 1536Kbps

Audio Codec相關設定

選擇MCLK當codec SYS_CLK.

1.  播放Sample Rate: 32KHz的設定,
   MCLK: 12.288MHz
   BCLK: 2.048MHz
   Stereo ADC/DAC Filter Clock Select = 384Fs= 384*32KHz = 12.288MHz = MCLK
   Voice I2S Master Mode Clock Relative of BCLK and LRCK = 64Fs = 64*32KHz = 2.048MHz = BCLK 
2. 播放Sample Rate: 44.1KHz的設定,
   MCLK: 11.289MHz (From CPU)
   BCLK: 2.82224MHz (64FS)
   Stereo ADC/DAC Filter Clock Select = 256Fs= 256*44.1KHz = 11.289MHz = MCLK
   Voice I2S Master Mode Clock Relative of BCLK and LRCK = 64Fs = 64*44.1KHz = 2.8224MHz = BCLK
3. 播放Sample Rate: 48KHz的設定,
   MCLK: 12.288MHz (From CPU)
   BCLK: 3.072MHz (64FS)
   Stereo ADC/DAC Filter Clock Select = 256Fs= 256*48KHz = 12.288MHz = MCLK
   Voice I2S Master Mode Clock Relative of BCLK and LRCK = 64Fs = 64*48KHz = 3.072MHz = BCLK