PIC18F4550，上电功能混乱，手动复位后运行正常

liuqian

环境：MPLABX IDE V1.8
编译器： XC8 C Compiler V1.12 免费版
烧写器：pickit3

功能：
CPU接了几个LED、一个20X2的LCD，串口。

现象：
用pickit3下载后，程序正常运行，LED闪动，串口发送接收，LCD显示。但是去掉pickit3之后，重新上电，串口和LED都正常，但LCD显示错位。但是短路MCLR，然后程序运行正常。
程序在main函数的开始，就先加了一个500ms的延时，然后才是初始化等，以防止上电不稳的情况。


复位电路：

C5试过 不接，15n，100n，10u，情况一样
R3试过 10K，3K，情况一样

电源：
换过两个，情况一样

配置位：WDT关闭
试过BOR的各种配置，情况一样
试过PWRTEN， 0 或1， 情况一样
试过MCLRE， 0 或1， 情况一样

百思不得其解，请各位支招，谢谢。

wye11083

复位电容太小！！！

liuqian

wye11083 发表于 2013-7-10 21:49
复位电容太小！！！

用了100n和10u的是同样现象

liuqian

配置位
// CONFIG1L
#pragma config PLLDIV = 5       // PLL Prescaler Selection bits (Divide by 5 (20 MHz oscillator input))
#pragma config CPUDIV = OSC1_PLL2// System Clock Postscaler Selection bits ([Primary Oscillator Src: /1][96 MHz PLL Src: /2])
#pragma config USBDIV = 1       // USB Clock Selection bit (used in Full-Speed USB mode only; UCFG:FSEN = 1) (USB clock source comes directly from the primary oscillator block with no postscale)

// CONFIG1H
#pragma config FOSC = HS        // Oscillator Selection bits (HS oscillator (HS))
#pragma config FCMEN = OFF      // Fail-Safe Clock Monitor Enable bit (Fail-Safe Clock Monitor disabled)
#pragma config IESO = OFF       // Internal/External Oscillator Switchover bit (Oscillator Switchover mode disabled)

// CONFIG2L
#pragma config PWRT = ON        // Power-up Timer Enable bit (PWRT enabled)
#pragma config BOR = OFF        // Brown-out Reset Enable bits (Brown-out Reset disabled in hardware and software)
#pragma config BORV = 3         // Brown-out Reset Voltage bits (Minimum setting)
#pragma config VREGEN = OFF     // USB Voltage Regulator Enable bit (USB voltage regulator disabled)

// CONFIG2H
#pragma config WDT = OFF        // Watchdog Timer Enable bit (WDT disabled (control is placed on the SWDTEN bit))
#pragma config WDTPS = 1        // Watchdog Timer Postscale Select bits (1:1)

// CONFIG3H
#pragma config CCP2MX = OFF     // CCP2 MUX bit (CCP2 input/output is multiplexed with RB3)
#pragma config PBADEN = OFF     // PORTB A/D Enable bit (PORTB<4:0> pins are configured as digital I/O on Reset)
#pragma config LPT1OSC = OFF    // Low-Power Timer 1 Oscillator Enable bit (Timer1 configured for higher power operation)
#pragma config MCLRE = ON       // MCLR Pin Enable bit (MCLR pin enabled; RE3 input pin disabled)

// CONFIG4L
#pragma config STVREN = OFF     // Stack Full/Underflow Reset Enable bit (Stack full/underflow will not cause Reset)
#pragma config LVP = OFF        // Single-Supply ICSP Enable bit (Single-Supply ICSP disabled)
#pragma config ICPRT = OFF      // Dedicated In-Circuit Debug/Programming Port (ICPORT) Enable bit (ICPORT disabled)
#pragma config XINST = OFF      // Extended Instruction Set Enable bit (Instruction set extension and Indexed Addressing mode disabled (Legacy mode))

// CONFIG5L
#pragma config CP0 = OFF        // Code Protection bit (Block 0 (000800-001FFFh) is not code-protected)
#pragma config CP1 = OFF        // Code Protection bit (Block 1 (002000-003FFFh) is not code-protected)
#pragma config CP2 = OFF        // Code Protection bit (Block 2 (004000-005FFFh) is not code-protected)
#pragma config CP3 = OFF        // Code Protection bit (Block 3 (006000-007FFFh) is not code-protected)

// CONFIG5H
#pragma config CPB = OFF        // Boot Block Code Protection bit (Boot block (000000-0007FFh) is not code-protected)
#pragma config CPD = OFF        // Data EEPROM Code Protection bit (Data EEPROM is not code-protected)

// CONFIG6L
#pragma config WRT0 = OFF       // Write Protection bit (Block 0 (000800-001FFFh) is not write-protected)
#pragma config WRT1 = OFF       // Write Protection bit (Block 1 (002000-003FFFh) is not write-protected)
#pragma config WRT2 = OFF       // Write Protection bit (Block 2 (004000-005FFFh) is not write-protected)
#pragma config WRT3 = OFF       // Write Protection bit (Block 3 (006000-007FFFh) is not write-protected)

// CONFIG6H
#pragma config WRTC = OFF       // Configuration Register Write Protection bit (Configuration registers (300000-3000FFh) are not write-protected)
#pragma config WRTB = OFF       // Boot Block Write Protection bit (Boot block (000000-0007FFh) is not write-protected)
#pragma config WRTD = OFF       // Data EEPROM Write Protection bit (Data EEPROM is not write-protected)

// CONFIG7L
#pragma config EBTR0 = OFF      // Table Read Protection bit (Block 0 (000800-001FFFh) is not protected from table reads executed in other blocks)
#pragma config EBTR1 = OFF      // Table Read Protection bit (Block 1 (002000-003FFFh) is not protected from table reads executed in other blocks)
#pragma config EBTR2 = OFF      // Table Read Protection bit (Block 2 (004000-005FFFh) is not protected from table reads executed in other blocks)
#pragma config EBTR3 = OFF      // Table Read Protection bit (Block 3 (006000-007FFFh) is not protected from table reads executed in other blocks)

// CONFIG7H
#pragma config EBTRB = OFF      // Boot Block Table Read Protection bit (Boot block (000000-0007FFh) is not protected from table reads executed in other blocks)

wye11083

LCD用的是SPI接口吧。检查上电SPI_CS有没有置高电平。

liuqian

LCD是1602的，用4位模式。
出现错误的情况是，本来应该在第二行的字符显示在了第一行，而且位置也不对。
但是如果把复位对地短路一下，运行就对了。

liuqian

搞定了，不是复位的问题，而是LCD初始化的问题，开始没有按照8为模式作3次设定，直接用4位模式作了3次。
短路复位，就相当于吧原来的LCD初始化部分又运行了一遍，LCD的初始化才真正完成，完成4位，2行的设置。

retome

厉害，没有搞过类似的，谢谢