关于模拟USART的问题

北斗星君

我现在用的是skyeye 1.23。

最近在调试 USART的读写程序(个人按照手册的提示写的)
但是我这边因为用的是笔记本，所以没有 串行口 因此，我想问一下如何使用键盘作为USART的输入，终端作为USART的输出。或者以普通文件作为USART的输入和输出。

谢谢赐教。

另外，想问一下，如何在skyeye中人为模拟产生硬件中断信号，比如CPU进入休眠状态，那么人为的在skyeye中模拟一个外部中断信号来将CPU唤醒，请问这个唤醒的外部中断如何在skyeye中模拟？

ksh

1. 当前skyeye默认用键盘和终端来作为usart的模拟输入和输出。具体代码在device/uart/skyeye_uart_stdio.c
2. 在每一个开发板模拟代码中的io_do_cycle函数，如skyeye_mach_ep7312.c的io_do_cycle函数。设置中断标志，并且跳转PC到中断处理函数

北斗星君

可是我这边的代码无法被正常执行。

我的C代码如下

1. 
   
2. void app(void){
   
3.   long* USART_THR=(long*)0xfffd001c;
   
4.   long* USART_RHR=(long*)0xfffd0018;
   
5.   long* USART_CSR=(long*)0xfffd0014;
   
6.   long stat;
   
7.   while(1){
   
8.     stat=*USART_CSR;
   
9.     if(stat&0x001){
   
10.       *USART_THR='M';
    
11.     }
    
12.   }
    
13.   while(1);
    
14.   return;
    
15. }
    

复制代码

我的skyeye的配置文件

1. 
   
2. #skyeye config file sample
   
3. cpu: arm7tdmi
   
4. 
   
5. mach: at91
   
6. 
   
7. mem_bank: map=M,type=RW,addr=0x01000000,size=0x00400000,file=app.bin,boot=yes
   
8. mem_bank: map=I,type=RW,addr=0xf0000000,size=0x10000000
   
9. log: logon=0,logfile=./sk1.log,start=0,end=200000
   

复制代码

当我向用键盘输入时，什么也没反应。可是按照代码，我每次输入都应该输出一个M的。

ksh

Please read helloworld example in this board.
http://www.linuxfans.org/bbs/thread-82187-1-1.html
You will get some idea from it.

北斗星君

那个我看过了，我的代码是按照手册上来的。应该没有问题的。

而且，我可以在屏幕上输出数据，但是，不能从键盘读数据

ksh

Try to debug it. I also think that should not be the mistake of SkyEye. At least uCos and uClinux for at91 can run correctly on SkyEye.

北斗星君

调试过了，代码没有问题。那如果既不是我的问题，按照KSH的说法，也不是skyeye的问题～，那这个是谁的问题呢？
我觉得推卸责任不是解决之道，不知道KSH接下来是不是又要说，It maybe the matter of your computer,.....？？？

ksh

I read the source code of skyeye and datasheet. There is two issues:
1. Perhaps RCR register need to be initialized before read data to RHR. Is it necessary? I am not familiar with the usart of AT91. There is a description related to it:
RXCTR must be loaded with the size of the receive buffer.

2. The implementation of SkyEye also is not incompletely. CSR is not set correctly.

Thanks your report.

[ 本帖最后由 ksh 于 2007-12-24 00:01 编辑 ]

ksh

I read the source code of skyeye and datasheet. There is two issues:
1. Perhaps RCR register need to be initialized before read data to RHR. Is it necessary? I am not familiar with the usart of AT91. There is a description related to it:
RXCTR must be loaded with the size of the receive buffer.

2. The implementation of SkyEye also is not incompletely. CSR is not set correctly.

Thanks your report.