EMERSON VE4003S6B1控制器
嵌入式PCI功能VMIVME-7750通过PCI总线提供非易失性RAM（NVRAM）、计时器和看门狗计时器。嵌入式和实时应用程序需要这些功能。这些嵌入式功能的PCI配置空间如下所示。“设备ID”字段表示该设备用于VME产品（00），并表示支持的嵌入式功能集。“供应商ID”和“子系统供应商ID”字段表示VMIC的PICMG分配的供应商ID（114A）。“子系统ID”字段表示产品的型号（7750）。概述VMIVME-7750提供四个用户可编程定时器（两个16位和两个32位），它们完全专用于用户应用，不需要任何标准系统功能。每个定时器由独立的发生器计时，频率可选择为2MHz、1MHz、500kHz和250kHz。每个定时器可以独立启用，并且每个定时器都能够在超时时生成系统中断。事件可以通过轮询计时器或启用计时器的中断功能来计时。状态寄存器允许应用软件确定哪个定时器是任何中断的原因。
Embedded PCI Functions The VMIVME-7750 provides non-volatile RAM (NVRAM), Timers and a Watchdog Timer via the PCI bus. These functions are required for embedded and real time applications. The PCI configuration space of these embedded functions are shown below.The “Device ID” field indicates that the device is for VME products (00) and indicates the supported embedded feature set. The “Vender ID” and “Subsystem Vendor ID” fields indicate VMIC’s PICMG assigned Vender ID (114A). The “Subsystem ID” field indicates the model number of the product (7750).General The VMIVME-7750 provides four user-programmable timers (two 16-bit and two 32-bit) which are completely dedicated to user applications and are not required for any standard system function. Each timer is clocked by independent generators with selectable rates of 2MHz, 1MHz, 500kHz and 250kHz. Each timer may be independently enabled and each is capable of generating a system interrupt on timeout. Events can be timed by either polling the timers or enabling the interrupt capability of the timer. A status register allows for application software to determine which timer is the cause of any interrupt.
