57160001-TZ DSTD110A PLC/DCS卡件模块
对于DMA通道1模式寄存器的正常操作
以下位应保持其默认值：0至6、12、14、15、19和22至31。为了启用更快的内存突发模式，该寄存器的第7位和第8位应从默认值零（0）更改为一（1）。DMA信道1模式寄存器的剩余位取决于用户所需的DMA模式。表3-52 DMA通道1模式寄存器DMA通道2模式：DMAMODE1，偏移$94位描述PCI复位1:0本地总线宽度后的读写值。写入00表示8位总线宽度。写入01表示16位总线宽度。写入10或11表示32位总线宽度。是是M=11 J=11 C=11 5:2内部等待状态（日期至今）。是是$0 6 TA#/READY#输入启用。写入一（1）启用TA#/READY#输入。写入零（0）将禁用TA#/READY#输入。是是17 BTERM#输入启用。写入一（1）启用BTERM#输入。写入零（0）将禁用BTERM#输入。有关更多信息，请参阅M、C和J模式。是是0 8本地突发启用。写一（1）表示本地突发。写入零（0）将禁用本地突发。是是0 9散射/聚集模式。写入一（1）表示“分散/聚集”模式已启用。对于分散/聚集模式，DMA源地址、目标地址和字节计数从PCI或本地地址空间中的内存加载。写入零（0）表示块模式已启用。是是0 10完成中断启用。写入一（1）将在完成时启用中断。写入零（0）完成后禁用中断。如果启用DMA清除计数模式，则在清除字节计数之前不会发生中断。是是0 11本地寻址模式。写入一（1）保持本地地址总线恒定。写入零（0）表示本地地址递增。是是0
Normal operation of DMA channel 1 mode register
The following bits should remain their default values: 0 to 6, 12, 14, 15, 19, and 22 to 31. To enable faster memory burst mode, bits 7 and 8 of this register should be changed from the default value of zero (0) to one (1). The remaining bits of the DMA channel 1 mode register depend on the DMA mode required by the user. Table 3-52 DMA Channel 1 Mode Register DMA Channel 2 Mode: DMAMODE1, offset $94 bit describes the read/write value after PCI resets 1:0 local bus width. Write 00 to indicate 8-bit bus width. Write 01 to indicate the 16 bit bus width. Writing 10 or 11 indicates the 32-bit bus width. Yes is M=11 J=11 C=11 5:2 internal waiting state (date to date). Yes Yes $0 6 TA #/READY # input enabled. Write one (1) to enable TA #/READY # input. Writing zero (0) disables TA #/READY # input. Yes is 17 BTERM # input enabled. Write one (1) to enable BTERM # input. Writing zero (0) disables BTERM # input. For more information, see M, C, and J Modes. Yes is 0 8 local burst enabled. Write one (1) to indicate a local burst. Writing zero (0) disables local bursts. Yes is 0 9 scatter/gather mode. Writing one (1) indicates that Scatter/Gather mode is enabled. For decentralized/aggregated mode, DMA source address, destination address and byte count are loaded from memory in PCI or local address space. Writing zero (0) indicates that block mode is enabled. Yes Yes 0 10 complete interrupt enable. Write one (1) will enable interrupts on completion. Disable interrupt when writing zero (0) is complete. If DMA clear count mode is enabled, no interrupt occurs until the byte count is cleared. Yes is 0 11 local addressing mode. Write one (1) to keep the local address bus constant. Writing zero (0) means that the local address is incremented. Yes Yes 0
