Part Number:TMS320F2812
如题,2812在正常工作时,EMU1是3.3的高电平,此时当引脚单独示波器时,DSP挂起,重新上电才能工作;
后来发现,在2812正常工作时,当将EMU1接GND时,就会导致DSP挂起.
想问一下:2812正常工作时,EMU1的逻辑变化会造成2812进入某些状态吗?
另外,EMU1引脚是不是特别敏感?
这些在2812datasheet上没有查到
Green Deng:
这个引脚在datasheet上有这样说明:
Emulator pin 1. When TRST is driven high, this pin is used as an interrupt to or from the emulator system and is defined as input/output through the JTAG scan. This pin is also used to put the device into boundary-scan mode. With the EMU0 pin at a logic-high state and the EMU1 pin at a logic-low state, a rising edge on the TRST pin would latch the device into boundary-scan mode. NOTE: An external pullup resistor is recommended on this pin. The value of this resistor should be based on the drive strength of the debugger pods applicable to the design. A 2.2-kΩ to 4.7-kΩ resistor is generally adequate. Since this is application-specific, it is recommended that each target board be validated for proper operation of the debugger and the application.
你的板子上这个引脚有接上拉电阻吗?
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kai tang:
EMU0和EMU1都接的10k上拉,在2812运行过程中EMU0接地没问题,EMU1接地就挂起
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Green Deng:
额,是不是接太高了。。。手册上要求的是2.2-kΩ ~ 4.7-kΩ。。。
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kai tang:
感觉这个影响不大吧,我今天查了查,EMU0在逻辑高电平,EMU1在逻辑低电平,且TRST出现上升沿的时候,会进入边界扫描模式,我感觉可能是这个问题.
这又有新的问题了:在DSP"挂起"(现在看可能不是挂起?)后,还能输出PWM信号,只是占空比不再更新,串口数据不再收发,请问进入边界扫描模式后,DSP的程序还在运行么?哪些模块还会正常工作呀?
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Green Deng:
哎,找了一圈没找到boundary-scan mode的资料,我也没研究过边界扫描,建议你将问题发送到英文E2E论坛咨询一下,那边会有BU级别的工程师可能会知道这方面的情况:e2e.ti.com/…/c2000-microcontrollers-forum