23LC1024四线访问数据

为什么需要四线串行访问23LC1024？

在“单片机片外RAM，串行的”中减少了对Microchip公司的SPI接口RAM芯片：23LC1024的读写测试。但是在STC8G1K08但潘辰的SPI接口驱动下，访问对其进行一次字节的读写操作，大概需要消耗20微妙的的时间，这使得在高速、高精度采集应用中跟不上数据的采集。

为了提高对其的访问速度，可以采用以下的方式：

使用其四线串行模式（SQI）的方式进行访问；
尽量使用序列读写方式，而不是每次完成完整的命令+地址+数据的腹泻方式

下面为了配合AD7606八通道AD采集模块测试中数据的采集，首先测试23LC1024在STC8G1K08操作下访问速度

本文实验中的工程文件可以在下面资源中下载：

23LC1024串行四线访问工程

实验电路设计

AD工程文件目录：

AD\Test\2020\TestAD7606STC\TestAD7606STC8G.SchDoc

1. 原理图

电路板设计中采用了STC8G1K08 TSOP20封装的芯片。核心板上集成了23LC1024串行接口的RAM，对于AD7606的接口是通过ADI10芯接口连接。

^{▲ 原理图}

2. PCB

设计电路PCB版图，适宜使用单面PCB板制作实验电路。

^{▲ 快速制版后的实验电路板}

3. 硬件调试

软件开发所在的目录：

C51\STC\Test\2020\testAD76068G1K\TestAD76068G.uvproj

置STC8G1K08的硬件选项配置如下：

^{▲ 单片机硬件选项配置}

主要性能测试

1. 测试单个字节读写的时间

测试标准写入函数在执行过程中，LC1024的CS的波形：

LC1024ByteWrite(0, 0, 0xff, 0xf)

写入时间为2us，CS的波形如下图所示：

^{▲ CS波形，时间为2.03us}

读出的时间也是2.0us，

LC1024ByteRead(0x0, 0x0, 0xff)

下面是在读的时候，CLK， SO1的波形。

^{▲ CLK，SD1的波形}

2. 连续字节读写

使用连续字节读写的方式读取多组字节。下面是读取连续10个字节。所需要的时间为8.57us。

LC1024ReadBegin(0x0, 0x0, 0x0);
LC1024WriteByte(0x0);
LC1024WriteByte(0x0);
LC1024WriteByte(0x0);
LC1024WriteByte(0x0);
LC1024WriteByte(0x0);
LC1024WriteByte(0x0);
LC1024WriteByte(0x0);
LC1024WriteByte(0x0);
LC1024WriteByte(0x0);
LC1024WriteByte(0x0);
LC1024ReadWriteEnd();

^{▲ 连续读取十个字节所需要的时间}

如果仅仅执行读取起始和结束的语句：

LC1024ReadBegin(0x0, 0x0, 0x0);
LC1024ReadWriteEnd();

所小号的时间为2us。这说明读取单个字节的时间大约为(8.57−2)/10=0.65μs\left( {8.57 - 2} \right)/10 = 0.65\mu s(8.57−2)/10=0.65μs左右。

这个速度与博文“扩展32KRAM的STC8H8K信号采集版”中，通过并口扩展RAM的一次读写时间0.532us的速度基本相当了。

通过这个时间可以说明，使用SQI（串行四线制）在连续读写的情况下可以达到与并口扩展RAM相当的速度。

即使是单个读写所消耗的2us的时间，也比在博文“单片机片外RAM，串行的”中读取单个字节所消耗19.2us将近快了10倍左右。

^{▲ 通电进行调试}

^{▲ 测量读写信号波形}

函数程序模块

相关LC1024读取的程序模块如下。

其中致的说明的是，在LC1024的初始化函数中，调用了LC1024Reset命令，就保证了LC1024成功进入SQI模式。

LC1024访问函数头文件：

/*
**==============================================================================
** LC1024L4.H:            -- by Dr. ZhuoQing, 2020-05-04
**
**  Description:
**
**==============================================================================
*/
#ifndef __LC1024L4__
#define __LC1024L4__
//------------------------------------------------------------------------------
#ifdef LC1024L4_GLOBALS#define LC1024L4_EXT
#else#define LC1024L4_EXT extern
#endif // LC1024L4_GLOBALS
//------------------------------------------------------------------------------
//==============================================================================
#define LC1024_CS           1, 5
#define LC1024_CLK          1, 4
#define LC1024_SO0          1, 0
#define LC1024_SO1          1, 1
#define LC1024_SO2          1, 2
#define LC1024_SO3          1, 3#define LC1024_CLK_PULSE    ON(LC1024_CLK),_nop_(),OFF(LC1024_CLK)
#define LC1024_SO_OUT       (P1M1 &= 0xf0, P1M0|=0xf)
#define LC1024_SO_IN        (P1M1 |= 0xf,  P1M0 &= 0xf0)//------------------------------------------------------------------------------void LC1024L4Init(void);//------------------------------------------------------------------------------
#define LC1024_READ         0x03            // Read data from memory areray beginning at selected address
#define LC1024_WRITE        0x02            // Write data to memory array beginning at selected address
#define LC1024_EDIO         0x3B            // Enter Dual I/O access(Enter SDI bus mode)
#define LC1024_EQIO         0x38            // Enter Quad I/O access
#define LC1024_RSTIO        0xFF            // Reset Dual and Quad I/O access
#define LC1024_RDMR         0x05            // Read Mode register
#define LC1024_WRMR         0x1             // Write Mode register#define LONG_3(w)           ((unsigned char)(w >> 24))
#define LONG_2(w)           ((unsigned char)(w >> 16))
#define LONG_1(w)           ((unsigned char)(w >> 8))
#define LONG_0(w)           ((unsigned char)w)//------------------------------------------------------------------------------
void LC1024Reset(void);
void LC1024EQIEnter(void);
void LC1024EQIExit(void);//------------------------------------------------------------------------------
unsigned char LC1024ByteRead(unsigned char ucAdd2, unsigned char ucAdd1, unsigned char ucAdd0);
void LC1024ByteWrite(unsigned char ucAdd2, unsigned char ucAdd1, unsigned char ucAdd0, unsigned char ucByte);//------------------------------------------------------------------------------
void LC1024ReadBegin(unsigned char ucAdd2, unsigned char ucAdd1, unsigned char ucAdd0);
void LC1024WriteBegin(unsigned char ucAdd2, unsigned char ucAdd1, unsigned char ucAdd0);
unsigned char LC1024ReadByte(void);
void LC1024WriteByte(unsigned char ucByte);
void LC1024ReadWriteEnd(void);//------------------------------------------------------------------------------
unsigned char LC1024ReadMode(void);
void LC1024WriteMode(unsigned char ucMode);//==============================================================================
//             END OF THE FILE : LC1024L4.H
//------------------------------------------------------------------------------
#endif // __LC1024L4__

LC1024的C语言程序。

/*
**==============================================================================
** LC1024L4.C:             -- by Dr. ZhuoQing, 2020-05-04
**
**==============================================================================
*///------------------------------------------------------------------------------
#define LC1024L4_GLOBALS        1              // Define the global variables
#include "LC1024L4.H"
#include "C51BASIC.H"
#include "STC8G.H"
#include "INTRINS.H"//------------------------------------------------------------------------------void LC1024L4Init(void) {PM_PP(LC1024_CS);PM_PP(LC1024_CLK);ON(LC1024_CS);OFF(LC1024_CLK);LC1024_SO_IN;LC1024Reset();LC1024EQIEnter();
}//------------------------------------------------------------------------------
void LC1024EQIEnter(void) {unsigned char i, ucMask, ucByte;ucByte = LC1024_EQIO;ucMask = 0x80;LC1024_SO_IN;PM_PP(LC1024_SO0);OFF(LC1024_CS);for(i = 0; i < 8; i ++) {if(ucByte & ucMask) ON(LC1024_SO0);else OFF(LC1024_SO0);ucMask >>= 1;LC1024_CLK_PULSE;}LC1024_SO_IN;ON(LC1024_CS);}void LC1024EQIExit(void) {LC1024_SO_OUT;P1 |= 0xf;OFF(LC1024_CS);LC1024_CLK_PULSE;LC1024_CLK_PULSE;LC1024_SO_IN;ON(LC1024_CS);}//------------------------------------------------------------------------------
unsigned char LC1024ByteRead(unsigned char ucAdd2, unsigned char ucAdd1, unsigned char ucAdd0) {unsigned char ucRet;LC1024_SO_OUT;OFF(LC1024_CS);P1 &= 0xf0;LC1024_CLK_PULSE;P1 |= 0x3;LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd2 >> 4);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd2 & 0xf);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd1 >> 4);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd1 & 0xf);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd0 >> 4);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd0 & 0xf);LC1024_CLK_PULSE;LC1024_SO_IN;LC1024_CLK_PULSE;                       // Dummy byteLC1024_CLK_PULSE;    ON(LC1024_CLK);ucRet = (P1 << 4);OFF(LC1024_CLK);ON(LC1024_CLK);ucRet |= (P1 & 0xf);OFF(LC1024_CLK);ON(LC1024_CS);return ucRet;}//------------------------------------------------------------------------------
void LC1024ByteWrite(unsigned char ucAdd2, unsigned char ucAdd1, unsigned char ucAdd0, unsigned char ucByte) {LC1024_SO_OUT;OFF(LC1024_CS);P1 &= 0xf0;LC1024_CLK_PULSE;P1 |= 0x2;LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd2 >> 4);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd2 & 0xf);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd1 >> 4);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd1 & 0xf);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd0 >> 4);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd0 & 0xf);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucByte >> 4);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucByte & 0xf);LC1024_CLK_PULSE;LC1024_SO_IN;ON(LC1024_CS);
}//------------------------------------------------------------------------------
unsigned char LC1024ReadMode(void) {unsigned char ucRet;OFF(LC1024_CS);LC1024_SO_OUT;    P1 &= 0xf0;LC1024_CLK_PULSE;P1 |= 0x5;LC1024_CLK_PULSE;LC1024_SO_IN;ON(LC1024_CLK);ucRet = (P1 << 4);OFF(LC1024_CLK);ON(LC1024_CLK);ucRet |= (P1 & 0xf);OFF(LC1024_CLK);ON(LC1024_CS);return ucRet;}//------------------------------------------------------------------------------
void LC1024ReadBegin(unsigned char ucAdd2, unsigned char ucAdd1, unsigned char ucAdd0) {LC1024_SO_OUT;OFF(LC1024_CS);P1 &= 0xf0;LC1024_CLK_PULSE;P1 |= 0x3;LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd2 >> 4);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd2 & 0xf);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd1 >> 4);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd1 & 0xf);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd0 >> 4);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd0 & 0xf);LC1024_CLK_PULSE;LC1024_SO_IN;LC1024_CLK_PULSE;                       // Dummy byteLC1024_CLK_PULSE;    }//------------------------------------------------------------------------------
void LC1024WriteBegin(unsigned char ucAdd2, unsigned char ucAdd1, unsigned char ucAdd0) {LC1024_SO_OUT;OFF(LC1024_CS);P1 &= 0xf0;LC1024_CLK_PULSE;P1 |= 0x2;LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd2 >> 4);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd2 & 0xf);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd1 >> 4);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd1 & 0xf);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd0 >> 4);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucAdd0 & 0xf);LC1024_CLK_PULSE;}unsigned char LC1024ReadByte(void) {unsigned char ucRet;ON(LC1024_CLK);ucRet = (P1 << 4);OFF(LC1024_CLK);ON(LC1024_CLK);ucRet |= (P1 & 0xf);OFF(LC1024_CLK);return ucRet;
}void LC1024WriteByte(unsigned char ucByte) {P1 &= 0xf0;P1 |= (ucByte >> 4);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucByte & 0xf);LC1024_CLK_PULSE;}//------------------------------------------------------------------------------
void LC1024ReadWriteEnd(void) {LC1024_SO_IN;ON(LC1024_CS);
}//------------------------------------------------------------------------------
void LC1024WriteMode(unsigned char ucMode) {LC1024_SO_OUT;OFF(LC1024_CS);P1 &= 0xf0;LC1024_CLK_PULSE;P1 |= 0x5;LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucMode >> 4);LC1024_CLK_PULSE;P1 &= 0xf0;P1 |= (ucMode & 0xf);LC1024_CLK_PULSE;ON(LC1024_CS);LC1024_SO_IN;
}//------------------------------------------------------------------------------
void LC1024Reset(void) {LC1024_SO_OUT;P1 |= 0xf;OFF(LC1024_CS);LC1024_CLK_PULSE;LC1024_CLK_PULSE;LC1024_CLK_PULSE;LC1024_CLK_PULSE;LC1024_CLK_PULSE;LC1024_CLK_PULSE;LC1024_CLK_PULSE;LC1024_CLK_PULSE;ON(LC1024_CS);LC1024_SO_IN;}//==============================================================================
//                END OF THE FILE : LC1024L4.C
//------------------------------------------------------------------------------