TCC89x串口设置要点

//=====================================================================
//TITLE:
// TCC89x串口设置要点
//AUTHOR:
// norains
//DATE:
// Thursday 29-March-2011
//Environment:
// Visual Studio 2005
// Windows CE 6.0
// Telechips TCC8900
//=====================================================================

对于Telechips的TCC89x系列来说，串口资源不可谓不丰富，整整六组串口，应该能满足大多数的应用场合了。

如果运行的是Windows CE操作系统的话，除去作为调试的Debug口，那么还剩下五组可供应用程序使用。而这五组串口的使能，并不需要做太多的工作，只需要书写相应的注册表数值即可。只不过比较可惜的的是，Telechips原版的注册表，只使能COM1~COM3这三组，而COM4和COM5只能自己动手。不过这对于经验丰富的开发者来说，并不是一件很难的事情，完全可以依样画瓢。只不过，有下面几点需要注意。
　　
1. COM_ChNum和COM_PortNum必须对应

COM_ChNum是串口的通道，COM_PortNum是对应的PIN脚，这两个数值都可以在注册表中进行设置。但这并不意味着，可以随意设置，而必须要按照如下的映射关系：

COM_ChNum	COM_PortNum
1	1
2	4
3	5
4	2
5	3

简单点来说，如果COM_ChNum为3的话，那么COM_PortNum就必须为5。为什么会有如此奇怪的关系呢？其实这是因为代码中规定的。打开Magellan/Src/LIB/SOC/UART/TCC89x/tca_serial.c文件，查看tca_serial_portinit函数，就可以发现代码中已经一一映射，如下图所示：
　

　

而注册表必须要和代码保持一致，所以COM_ChNum和COM_PortNum的关系也就定死了。

2. DMA不支持Channel4~Channel5

这个要点在Datasheet的800页有如下的说明：



翻译为中文，大致是：DMA发送和接收在UART的Channel0~3是可用的。但如果是Channel4和Channel5，因为无法使用硬件控制，所以无法DMA。如果一定要使用DMA传输方式，请确保使用的是Channel0~3。

因为在Telechips的默认注册表中，Channel0~3已经被调试口和COM1~COM3所使用了，剩下的COM4和COM5只能放弃DMA的方式。而具体到注册表，则是"USEDMATX"和"USEDMARX"这两个键值的数值必须为0。

最后，则是看看完整的串口设置信息列表，Telechips没有给出的COM4和COM5设置也一并在表格中列出：

序号	Channel	Port	Tx	Rx	注册表	DMA
Debug	0	0	GPIO E[0]	GPIO E[1]	无	支持
COM1	3	5	GPIO D[17]	GPIO D[18]	[HKEY_LOCAL_MACHINE/Drivers/BuiltIn/Serial1] "DeviceArrayIndex"=dword:0 "COM_ChNum"=dword:3 "COM_PortNum"=dword:5 "MemBase"=dword:B100C000 "irq"=dword:2F "MemLen"=dword:2C "InterruptBitsShift"=dword:0 ; UART 0 Interrupt Sub Register shift bit. "ISTTimeouts"=dword:200 ; every 512 ticks checking Modem status. "Prefix"="COM" "Index"=dword:1 "Dll"="tcc_serial.dll" "Order"=dword:1 "Priority256"=dword:e0 "Port"="COM1:" "DeviceType"=dword:0 "FriendlyName"="Serial Cable on COM1:" "Tsp"="unimodem.dll" "IsrDll"="tcc_giisr.dll" "IsrHandler"="ISRHandler" "DMAIsrHandler"="DMAUARTISRHandler" "USEDMATX"=dword:1 ; 1:on 0:off "USEDMARX"=dword:0 ; 1:on 0:off "IClass"="{CC5195AC-BA49-48a0-BE17-DF6D1B0173DD}" "DevConfig"=hex: 10,00, 00,00, 05,00,00,00, 10,01,00,00, 00,4B,00,00, 00,00, 08, 00, 00, 00,00,00,00	支持
COM2	1	1	GPIO E[4]	GPIO E[5]	[HKEY_LOCAL_MACHINE/Drivers/BuiltIn/Serial2] "DeviceArrayIndex"=dword:1 "COM_ChNum"=dword:1 "COM_PortNum"=dword:1 "MemBase"=dword:B1008000 "irq"=dword:2F "MemLen"=dword:2C "InterruptBitsShift"=dword:0 ; UART Interrupt Sub Register shift bit. "ISTTimeouts"=dword:200 ; every 512 ticks checking Modem status. "Prefix"="COM" "Index"=dword:2 "Dll"="tcc_serial.dll" "Order"=dword:1 "Priority256"=dword:e0 "Port"="COM2:" "DeviceType"=dword:0 "FriendlyName"="Serial Cable on COM2:" "Tsp"="unimodem.dll" "IsrDll"="tcc_giisr.dll" "IsrHandler"="ISRHandler" "DMAIsrHandler"="DMAUARTISRHandler" "USEDMATX"=dword:1 ; 1:on 0:off "USEDMARX"=dword:1 ; 1:on 0:off "IClass"="{CC5195AC-BA49-48a0-BE17-DF6D1B0173DD}" "DevConfig"=hex: 10,00, 00,00, 05,00,00,00, 10,01,00,00, 00,4B,00,00, 00,00, 08, 00, 00, 00,00,00,00	支持
COM3	2	4	GPIO D[13]	GPIO D[14]	[HKEY_LOCAL_MACHINE/Drivers/BuiltIn/Serial3] "DeviceArrayIndex"=dword:2 "COM_ChNum"=dword:2 "COM_PortNum"=dword:4 "MemBase"=dword:B1004000 "irq"=dword:2F "MemLen"=dword:2C "InterruptBitsShift"=dword:0 ; UART Interrupt Sub Register shift bit. "ISTTimeouts"=dword:200 ; every 512 ticks checking Modem status. "Prefix"="COM" "Index"=dword:3 "Dll"="tcc_serial.dll" "Order"=dword:1 "Priority256"=dword:e0 "Port"="COM3:" "DeviceType"=dword:0 "FriendlyName"="Serial Cable on COM3:" "Tsp"="unimodem.dll" "IsrDll"="tcc_giisr.dll" "IsrHandler"="ISRHandler" "DMAIsrHandler"="DMAUARTISRHandler" "USEDMATX"=dword:1 ; 1:on 0:off "USEDMARX"=dword:1 ; 1:on 0:off "IClass"="{CC5195AC-BA49-48a0-BE17-DF6D1B0173DD}" "DevConfig"=hex: 10,00, 00,00, 05,00,00,00, 10,01,00,00, 00,4B,00,00, 00,00, 08, 00, 00, 00,00,00,00	支持
COM4	4	2	GPIO E[8]	GPIO E[9]	[HKEY_LOCAL_MACHINE/Drivers/BuiltIn/Serial4] "DeviceArrayIndex"=dword:3 "COM_ChNum"=dword:4 "COM_PortNum"=dword:2 "MemBase"=dword:B1000000 "irq"=dword:2F "MemLen"=dword:2C "InterruptBitsShift"=dword:0 ; UART Interrupt Sub Register shift bit. "ISTTimeouts"=dword:200 ; every 512 ticks checking Modem status. "Prefix"="COM" "Index"=dword:4 "Dll"="tcc_serial.dll" "Order"=dword:1 "Priority256"=dword:e0 "Port"="COM4:" "DeviceType"=dword:0 "FriendlyName"="Serial Cable on COM4:" "Tsp"="unimodem.dll" "IsrDll"="tcc_giisr.dll" "IsrHandler"="ISRHandler" "DMAIsrHandler"="DMAUARTISRHandler" "USEDMATX"=dword:0 ; 1:on 0:off "USEDMARX"=dword:0 ; 1:on 0:off "IClass"="{CC5195AC-BA49-48a0-BE17-DF6D1B0173DD}" "DevConfig"=hex: 10,00, 00,00, 05,00,00,00, 10,01,00,00, 00,4B,00,00, 00,00, 08, 00, 00, 00,00,00,00	不支持
COM5	5	3	GPIO E[10]	GPIO E[11]	[HKEY_LOCAL_MACHINE/Drivers/BuiltIn/Serial5] "DeviceArrayIndex"=dword:4 "COM_ChNum"=dword:5 "COM_PortNum"=dword:3 "MemBase"=dword:B0FFC000 "irq"=dword:2F "MemLen"=dword:2C "InterruptBitsShift"=dword:0 ; UART Interrupt Sub Register shift bit. "ISTTimeouts"=dword:200 ; every 512 ticks checking Modem status. "Prefix"="COM" "Index"=dword:5 "Dll"="tcc_serial.dll" "Order"=dword:1 "Priority256"=dword:e0 "Port"="COM5:" "DeviceType"=dword:0 "FriendlyName"="Serial Cable on COM5:" "Tsp"="unimodem.dll" "IsrDll"="tcc_giisr.dll" "IsrHandler"="ISRHandler" "DMAIsrHandler"="DMAUARTISRHandler" "USEDMATX"=dword:0 ; 1:on 0:off "USEDMARX"=dword:0 ; 1:on 0:off "IClass"="{CC5195AC-BA49-48a0-BE17-DF6D1B0173DD}" "DevConfig"=hex: 10,00, 00,00, 05,00,00,00, 10,01,00,00, 00,4B,00,00, 00,00, 08, 00, 00, 00,00,00,00	不支持