計算機控制外文翻譯

1、<p>　　11 Shift Instructions</p><p>　　11.1 Overview of Shift Instructions</p><p>　　11.1.1 Description</p><p>　　You can use the Shift instructions to move the contents of input I

2、N bit by bit to the left or the right (see also CPU Registers).Shifting to the left multiplies the contents of input IN by 2 to the power n (2n);shifting to the right divides the contents of input IN by 2 to the power n

3、(2n).</p><p>　　The number that you supply for input parameter N indicates the number of bits by which to shift.The bit places that are vacated by the Shift instruction are either filled with zeros or with th

4、e signal state of the sign bit (a0 stands for positive and a1 stands for negative).The signal state of the bit that is shifted last is loaded into the CC1 bit of the status word.The CC0 and OV bits of the status word are

5、 reset to 0.You can use jump instructions to evaluate the CC1 bit.</p><p>　　The following shift instructions are available:</p><p>　　SHR_I Shift Right Integer</p><p>　　SHR_DI Shift

6、Right Double Integer</p><p>　　SHL_W Shift Left Word</p><p>　　SHR_W Shift Right Word</p><p>　　SHL_DW Shift Left Double Word</p><p>　　SHR_DW Shift Right Double Word</p

7、><p>　　11.2 SHR_I Shift Right Integer</p><p>　　11.2.1 Symbol</p><p>　　11.2.2 Description</p><p>　　SHR_I(Shift Right Integer) is activated by a logic "1" at the E

8、nable (EN) Input.The SHR_I instruction is used to shift bits 0 to 15 of input IN bit by bit to the right.Bits 16 to 31 are not affected.The input N specifies the number of bits by which to shift.If N is larger than 16,th

9、e command acts as if N were equal to 16.The bit positions shifted in from the left to fill vacated bit positions are assigned the logic state of bit 15 (sign bit for the integer).This means these bit positions are ass<

10、;/p><p>　　ENO has the same signal state as EN.</p><p>　　11.2.3 Example</p><p>　　The SHR_I box is activated by logic "1" at I0.0.MW0 is loaded and shifted right by the number

11、of bits specified with MW2.The result is written to MW4. 4.0 is set. </p><p>　　11.3 SHR_DI Shift Right Double Integer</p><p>　　11.3.1 Symbol</p><p>　　11.3.2 Description</p>&

12、lt;p>　　SHR_DI (Shift Right Double Integer) is activated by a logic "1" at the Enable (EN) Input.The SHR_DI instruction is used to shift bits 0 to 31 of input IN bit by bit to the right. The input N specifie

13、s the number of bits by which to shift. If N is larger than 32,the command acts as if N were equal to 32.The bit positions shifted in from the left to fill vacated bit positions are assigned the logic state of bit 31 (si

14、gn bit for the double integer).This means these bit positions are assigned "0" i</p><p>　　ENO has the same signal state as EN.</p><p>　　11.3.3 Status word</p><p>　　11.4 SH

15、L_W Shift Left Word</p><p>　　11.4.1 Symbol</p><p>　　11.4.2 Description</p><p>　　SHL_W (Shift Left Word) is activated by a logic "1" at the Enable (EN) Input.The SHL_W inst

16、ruction is used to shift bits 0 to 15 of input IN bit by bit to the left.Bits 16 to 31 are not affected.The input N specifies the number of bits by which to shift.If N is larger than 16,the command writes a "0"

17、 at output OUT and sets the bits CC0 and OV in the status word to "0".N zeros are also shifted in from the right to fill vacated bit positions. </p><p>　　11.4.3 Example</p><p>　　The SH

18、L_W box is activated by logic "1" at I0.0.MW0 is loaded and shifted left by the number of bits specified with MW2.The result is written to MW4. Q4.0 is set.MW0 is loaded and shifted left by the number of bits s

19、pecified with MW2.</p><p>　　11.4.4 Status word</p><p>　　11.5 SHR_W Shift Right Word</p><p>　　11.5.1 Symbol</p><p>　　11.5.2 Description</p><p>　　SHR_W (Shif

20、t Right Word) is activated by a logic "1" at the Enable (EN) Input.The SHR_W instruction is used to shift bits 0 to 15 of input IN bit by bit to the right.Bits 16 to 31 are not affected.The input N specifies th

21、e number of bits by which to shift.If N is larger than 16, the command writes a "0" at output OUT and sets the bits CC0 and OV in the status word to "0".N zeros are also shifted in from the left to fi

22、ll vacated bit positions.The result of the shift instruction can be scanned at </p><p>　　ENO has the same signal state as EN.</p><p>　　11.5.3 Example</p><p>　　The SHR_W box is activ

23、ated by logic "1" at I0.0.MW0 is loaded and shifted right by the number of bits specified with MW2.The result is written to MW4. Q4.0 is set.</p><p>　　11.6 SHL_DW Shift Left Double Word</p>

24、<p>　　11.6.1 Symbol</p><p>　　11.6.2 Description</p><p>　　SHL_DW (Shift Left Double Word) is activated by a logic "1" at the Enable (EN) Input. The SHL_DW instruction is used to sh

25、ift bits 0 to 31 of input IN bit by bit to the left.The input N specifies the number of bits by which to shift.If N is larger than 32,the command writes a "0" at output OUT and sets the bits CC0 and OV in the s

26、tatus word to "0".N zeros are also shifted in from the right to fill vacated bit positions.The result double word of the shift instruction can be scanned at output OUT.</p><p>　　ENO has the same si

27、gnal state as EN.</p><p>　　11.6.3 Example</p><p>　　The SHL_DW box is activated by logic "1" at I0.0.MD0 is loaded and shifted left by the number of bits specified with MW4.The result i

28、s written to MD10.Q4.0 is set.</p><p>　　11.7 SHR_DW Shift Right Double Word</p><p>　　11.7.1 Symbol</p><p>　　11.7.2 Description</p><p>　　SHR_DW (Shift Right Double Word)

29、 is activated by a logic "1" at the Enable (EN)Input.The SHR_DW instruction is used to shift bits 0 to 31 of input IN bit by bit to the right.The input N specifies the number of bits by which to shift.If N is l

30、arger than 32, the command writes a "0" at output OUT and sets the bits CC0 and OV in the status word to "0". The result double word of the shift instruction can be scanned at output OUT.</p>&

31、lt;p>　　ENO has the same signal state as EN.</p><p>　　11.7.3 Example</p><p>　　The SHR_DW box is activated by logic "1" at I0.0.MD0 is loaded and shifted right by the number of bits s

32、pecified with MW4.The result is written to MD10.Q4.0 is set.</p><p>　　11.7.4 Status word</p><p><b>　　11 移位指令</b></p><p>　　11.1．移位指令概述</p><p>　　11.1.1 描述 <

33、;/p><p>　　可使用移位指令向左或向右逐位移動輸入IN的內(nèi)容（另請參閱CPU寄存器）。向左移n位會將輸入IN的內(nèi)容乘以2的n次冪（2n）；向右移n位則會將輸入IN的內(nèi)容除以2的n次冪（2n）。例如，如果將十進制數(shù)值“3”的等效二進制數(shù)左移3位，則累加器中的結(jié)果是十進制數(shù)“24”的二進制數(shù)。</p><p>　　您為輸入?yún)?shù)N提供的數(shù)值指示要移動的位數(shù)。由移位指令移空的位會用零或符號位的信

34、號狀態(tài)（“0”表示“正”，“1”表示“負”）補上。最后移動的位的信號狀態(tài)會被載入狀態(tài)字的CC1位中。狀態(tài)字的CC0位和OV位會被復(fù)位為0?？梢允褂锰D(zhuǎn)指令來評估CC1位。輸入?yún)?shù)N提供的數(shù)值表示移動的位數(shù)。狀態(tài)字的CC0和OV位清零。</p><p>　　可使用如下移位指令：</p><p>　　SHR_I 整數(shù)右移 </p><p>　　SHR_DI

35、 長整數(shù)右移 </p><p>　　SHL_W 字左移 </p><p>　　SHR_W 字右移 </p><p>　　SHL_DW 雙字左移 </p><p>　　SHR_DW 雙字右移 </p><p>　　11.2 SHR_I整數(shù)右移</p>

36、<p><b>　　11.2.1 符號</b></p><p>　　11.2.2 描述 </p><p>　　SHR_I（整數(shù)右移）指令通過使能（EN）輸入位置上的邏輯“1”來激活。SHR_I指令用于將輸入IN的0至15位逐位向右移動。16位到31位不受影響。輸入N用于指定移位的位數(shù)。如果輸入N值大于16，命令將按照N等于16的情況執(zhí)行。自左移入的、用于填補

37、空出位的位位置將被賦予位15的邏輯狀態(tài)（整數(shù)的符號位）。這意味著，當(dāng)該整數(shù)為正時，這些位將被賦值“0”，而當(dāng)該整數(shù)為負時，則被賦值為“1”?？稍谳敵鯫UT位置掃描移位指令的結(jié)果。如果N不等于0，則SHR_I會將CC0位和OV位設(shè)為“0”。</p><p>　　ENO與EN具有相同的信號狀態(tài)。</p><p><b>　　11.2.3 實例</b></p>

38、<p>　　如果I0.0為邏輯“1”，則SHR_I方塊激活。MW0裝入，并右移使用MW2指定的位數(shù)。其結(jié)果被寫入MW4中。Q4.0置位。</p><p>　　11.3 SHR_DI右移長整數(shù)</p><p><b>　　11.3.1 符號</b></p><p>　　11.3.2 描述 </p><p>　　

39、SHR_DI（雙整數(shù)右移指令）可以由使能（EN）輸入端的邏輯“1”信號激活。SHR_DI指令用于將輸入IN位的位0到位31逐位右移。輸入N指定移位的位數(shù)。如果N大于32，則該命令的作用和N等于32時一樣。從左邊到需填充空出位的所有移位都根據(jù)位31的信號狀態(tài)填充（這是一個整數(shù)的符號位）。這就意味著，如果整數(shù)為正值，則這些位被賦值“0”；如果整數(shù)為負值，則這些位被賦值“1”。移位操作的結(jié)果可以在輸出OUT中掃描。如果N不等于“0”，則通過S

40、HR_DI指令將CC0位和OV位清零。結(jié)果在輸出OUT得出。</p><p>　　ENO和EN具有相同的信號狀態(tài)。</p><p>　　11.3.3 狀態(tài)字</p><p>　　11.4 SHL_W字左移</p><p><b>　　11.4.1 符號</b></p><p>　　11.4.2 描

41、述 </p><p>　　SHL_W（字左移）指令通過使能（EN）輸入位置上的邏輯“1”來激活。SHL_W指令用于將輸入IN的0位至15位逐位向左移動。輸入N用于指定移位的位數(shù)。若N大于16，命令將按照N等于16的情況執(zhí)行。此命令會在輸出OUT位置上寫入“0”，并將狀態(tài)字中的CC0和OV位設(shè)置為“0”。將自右移入N個零，用以補上空出的位位置?？稍谳敵鯫UT位置掃描移位指令的結(jié)果。如果N不等于0，則SHL_W會將C

42、C0位和OV位設(shè)為“0”。</p><p>　　ENO與EN具有相同的信號狀態(tài)。</p><p><b>　　11.4.3 實例</b></p><p>　　SHL_W框由I0.0位置上的邏輯“1”激活。裝載MW0并將其左移由MW2指定的位數(shù)。結(jié)果將被寫入MW4。所得的結(jié)果將置位Q4.0。</p><p><b&g

43、t;　　11.4.4狀態(tài)字</b></p><p>　　11.5 SHR_W字右移</p><p><b>　　11.5.1 符號</b></p><p>　　11.5.2 描述 </p><p>　　SHR_W（字右移指令）可以由使能（EN）輸入端的邏輯“1”信號激活。SHR_W指令用于將輸入IN位的位0到

44、位15逐位右移。位16到位31不受影響。輸入N指定移位的位數(shù)。如果N大于16，該命令將“0”寫入輸出OUT，并將狀態(tài)字中的位CC0和OV清零。從左邊到需填充空出位的所有位將填入N個零。移位操作的結(jié)果可以在輸出OUT中掃描。如果N不等于“0”，則通過SHR_W指令將CC0位和OV位清零。</p><p>　　ENO和EN具有相同的信號狀態(tài)。</p><p><b>　　11.5.3

45、 實例</b></p><p>　　SHR_W框由I0.0位置上的邏輯“1”激活。裝載MW0并將其右移由MW2指定的位數(shù)。結(jié)果將被寫入MW4。置位Q4.0。</p><p>　　11.6 SHL_DW雙字左移</p><p><b>　　11.6.1 符號</b></p><p>　　11.6.2 描述 &l

46、t;/p><p>　　SHL_DW（雙字左移指令）可以由使能（EN）輸入端的邏輯“1”信號激活。SHL_DW指令用于將輸入IN位的位0到位31逐位左移。輸入N指定移位的位數(shù)。如果N大于32，該命令將“0”寫入輸出OUT，并將狀態(tài)字中的位CC0和OV清零。從右邊到需填充空出位的所有位將填入N個零。雙字移位操作的結(jié)果可以在輸出OUT中掃描。如果N不等于“0”，則通過SHL_DW指令將CC0位和OV位清零。</p&g

47、t;<p>　　ENO和EN具有相同的信號狀態(tài)。</p><p><b>　　11.6.3 實例</b></p><p>　　SHL_DW框由I0.0位置上的邏輯“1”激活。裝載MD0并將其左移由MW4指定的位數(shù)。結(jié)果將被寫入MD10。置位Q4.0。</p><p>　　11.7 SHR_DW雙字右移</p><

48、;p><b>　　11.7.1 符號</b></p><p>　　11.7.2 描述 </p><p>　　SHR_DW（雙字右移指令）可以由使能（EN）輸入端的邏輯“1”信號激活。SHR_DW 指令用于將輸入IN位的位0到位31逐位右移。輸入N指定移位的位數(shù)。如果N大于32，該命令將“0”寫入輸出OUT，并將狀態(tài)字中的位CC0和OV清零。從左邊到需填充空出位的

49、所有位將填入N個零。雙字移位操作的結(jié)果可以在輸出OUT中掃描。如果N不等于“0”，則通過 SHR_DW指令將CC 0位和OV位清零。</p><p>　　ENO和EN具有相同的信號狀態(tài)。</p><p><b>　　11.7.3 實例</b></p><p>　　SHR_DW框由I0.0位置上的邏輯“1”激活。裝載MD0并將其右移由MW4指定的