V850ES/Kx2 Microcontrollers Usage Restrictions
Contents
1. 1 ends at the same time as the instruction in 2 accesses the internal RAM 2 For a mul or mulu instruction the operation described in this restriction occurs if ro is specified for the third operand reg3 or the same register is specified for the second operand reg2 and third operand reg3 as shown below mul reg1 reg2 reg3 reg3 r0 or reg2 reg3 mul imm9 reg2 reg3 reg3 r0 or reg2 reg3 mulu regl reg2 reg3 reg3 r0 or reg2 reg3 mulu imm9 reg2 reg3 reg3 r0 or reg2 reg3 For a program written in C the CA850 does not generate the mul and mulu instructions if the same register is specified for the reg2 and reg3 operands 3 This restriction applies if it takes 2 clock cycles or less between the instructions in 3 and 4 This restriction does not apply in any of the following cases An external bus is not used The data read by the load instruction in 1 is used to specify the target address of the load instruction in 2 The data read by the load instruction in 1 is referenced by an instruction executed between the instructions in 1 and 2 The data read by the load instruction in 2 is referenced by the multiplication instruction in 3 The data obtained by the multiplication instruction in 3 is used to specify the target address of the load instruction in 4 The data obtained by the multiplication instruction in 3 is referenced by an instruction executed between the instructions2. Schedule Version After Upgrade SP850 V3 40 V3 42 Japanese November 9 2009 CA850 English November 9 2009 Action for already developed systems Use the interview sheet in attachment 2 to check whether the restriction applies Application of this restriction to embedded software products This restriction applies to NEC Electronics real time OSs and middleware as follows e Real time OSs RX850 The restriction does not apply RX850 Pro The restriction does not apply RX850V4 The restriction does not apply e Middleware GOFAST The restriction does not apply JPEG The restriction does not apply For products other than the above contact an NEC Electronics sales representative For third party products contact the vendor of the product Modification The device will not be corrected so regard this restriction as a specification Use the latest compiler to avoid this restriction 3 Development environment required to work around this restriction Use NEC Electronics compiler CA850 V3 42 or later Note that the outputs from the above version might differ from the outputs from the older versions If you are using another compiler contact an NEC Electronics sales representative 4 Document revision history Document Number ZBG CC 09 0037 November 9 2009 1st edition Restriction no 1 ZBG CC 09 0037 Attachment 1 1 1 V850ES Kx2 Microcontroller Usage Restrictions Restriction Nickname Product Deve
3. Document No ZBG CC 09 0037 Date issued November 9 2009 Issued by Product Solution Group Multipurpose Microcomputer Systems Division Microcomputer Operations Unit NEC Electronics Corporation V850ES Kx2 Microcontrollers Usage Restrictions Related documents Notification y Usage restriction V850ES KF2 Hardware User s Manual classification Upgrade U17704EJ2VOUDO0 2nd edition Document modification V850ES KG2 Hardware User s Manual U17703EJ3VOUDO00 3rd edition V850ES KJ2 Hardware User s Manual U17702EJ3VOUD00 3rd edition V850ES Architecture User s Manual U15943EJ3VOUMO0 3rd edition Other notification 1 Affected products V850ES Kx2 microcontrollers except for V850ES KE2 V850ES KF2 uPD70F3728 uPD70F3729 V850ES KG2 uPD70F3731 uPD70F3732 V850ES KJ2 uPD70F3733 uPD70F3734 2 Notification The following restriction for the V850ES Kx2 microcontrollers has been found No 1 Restriction on executing a mul or mulu instruction Description The following occur if a specific instruction sequence sequence 1 or 2 below is executed e The result of executing a multiplication instruction is not stored in the relevant general purpose register e As a result of executing an 1d instruction for a mis aligned address the data at an incorrect address is read and stored in the relevant general purpose register Sequence 1 In the following instruction sequence the RAM is read by one o
4. ation instruction in 3 The data obtained by the multiplication instruction in 3 is used to specify the target address of the load instruction in 4 The data obtained by the multiplication instruction in 3 is referenced by an instruction executed between the instructions in 3 and 4 At least one of the following instructions is executed between the instructions in 3 and 4 gt A multiplication instruction mul mulh mulhi mulu gt Abit manipulation instruction clr1 not1 set1 tst1 gt A special instruction callt dispose switch The instruction in 4 is a load instruction that accesses the memory in bytes 1d b 1d bu sld b or sld bu The instructions in 1 to 4 are located in an external memory or the internal RAM Sequence 2 In the following instruction sequence access by the instruction in 1 ends at the same time as the instruction in 2 accesses the internal RAM 1 ldorsid A load instruction for an external memory 2 1 3 mul or mulu An instruction that multiplies word data and whose result is truncated to 32 bits Note 1 dorsid A load instruction for the internal RAM Note 2 Note 3 4 ldorsid A load instruction for a mis aligned address in the internal ROM or RAM ZBG CC 09 0037 3 4 Notes 1 This restriction applies if a different instruction is executed between the load instructions in 1 and 2 and the access by the instruction in
5. dgment using check tools func
6. f the instructions in 2 at the same time as the RAM is accessed by a DMA transfer 1 1ldorsid A load instruction for the internal ROM 2 1dorsid A load instruction for the internal RAM 3 mul or mulu An instruction that multiplies word data and whose result is truncated to 32 bits t 1 Note 2 4 ldorsid A load instruction for a mis aligned address in the internal ROM or RAM ZBG CC 09 0037 2 4 Notes 1 For a mul or mulu instruction the operation described in this restriction occurs if ro is specified for the third operand reg3 or the same register is specified for the second operand reg2 and third operand reg3 as shown below mul reg1 reg2 reg3 reg3 r0 or reg2 reg3 mul imm9 reg2 reg3 reg3 r0 or reg2 reg3 mulu reg1 reg2 reg3 reg3 r0 or reg2 reg3 mulu imm9 reg2 reg3 reg3 r0 or reg2 reg3 For a program written in C the CA850 does not generate the mul and mulu instructions if the same register is specified for the reg2 and reg3 operands 2 This restriction applies if it takes 2 clock cycles or less between the instructions in 3 and 4 This restriction does not apply in any of the following cases DMA is not used to transfer data to or from the internal RAM The data read by the load instruction in 1 is used to specify the target address of the load instruction in 2 The data read by the load instruction in 2 is referenced by the multiplic
7. in 3 and 4 At least one of the following instructions is executed between the instructions in 3 and 4 gt A multiplication instruction mul mulh mulhi mulu gt Abit manipulation instruction clr1 not1 set1 tst1 gt A special instruction callt dispose switch The instruction in 4 is a load instruction that accesses the memory in bytes 1d b 1d bu s1d b or sld bu The instructions in 1 to 4 are located in an external memory or the internal RAM Workaround Action for systems being developed and to be developed in future We regard this as a restriction related to the CPU s features and do not intend to correct the microcontroller Instead the CA850 compiler will be modified to automatically prevent instructions to which this restriction applies from being generated This workaround does not work for instructions in assembly code so the CA850 outputs a message for such instructions How NEC Electronics will provide the update for the compiler is shown below If you are using another compiler contact an NEC Electronics sales representative ZBG CC 09 0037 4 4 e f your compiler is the NEC Electronics compiler CA850 The CA850 will be upgraded to add the above workaround The following table shows the version and release schedule for the C compiler package CA850 and the software package SP850 that includes the CA850 Product Name Current CA850 Version of CA850 Language Release
8. lopment Environment in Which the Restriction Can Be Worked Around Restriction on executing a mul or V850ES HPD70F3726 mulu instruction KE2 V850ES HPD70F3728 Category Compiler KF2 LPD70F3729 Product name CA850 V850ES LPD70F3731 Version V3 42 or later KG2 HPD70F3732 V850ES LPD70F3733 KJ2 LPD70F3734 Note Whether or not the restriction applies Remark The meaning of each symbol for Note is as follows Restriction does not apply Restriction is already corrected Restriction applies correction is planned Restriction applies correction is not planned gt x 2 ZBG CC 09 0037 Attachment 2 1 2 e First judgment Judgment based on product usage conditions Check the conditions under which you are using the product to see whether the restriction applies to the product If the restriction might apply perform a second judgment If the restriction is judged to be not applicable subsequent checking is not necessary m Checking the usage conditions Select Yes or No for whether the features in 1 and 2 below are used If the product does not incorporate a feature select Not relevant for the feature If there is no item for which Yes is selected the restriction does not apply 1 Data is not transferred to or from the internal RAM using DMA Yes No Not relevant 2 An external bus interface is used O Yes No Not relevant ZBG CC 09 0037 At
9. rce code and misalign_pack is specified as a compiler option 2 pack 1 or pack 2 and misalign_pack are specified as compiler options Checking the Is structure packing specified Note 2 Use the check tool for the assembly list When executing the char ptr_char abcdef check tool specify int data ptr_int the Missalign Y p option ptr_int int ptr_char 2 data ptr_int Is the source code available and is the CA850 or a GHS compiler used Go to third judgment No using check tools Use the check tool for hex objects When executing the check tool specify the Missalign Y Yes Is there assembly option code No Is accessing a mis 7 aligned address specified Waone end intentionally in the C Yes check tools source Note 3 Use the check tool for the assembly list When executing the check tool specify the Missalign Y option No Is the compiler CA850 made by NECEL used Yes CA850 No GHS compiler Is structure packing at compile time specified Note 1 2 at compile time No Restriction does not apply Yes Yes Note 3 A mis aligned address might be accessed if a pointer to a char is cast to a pointer to an int to reference the int as shown below Go to third ju
10. tachment 2 2 2 e Second judgment Judgment based on compiling conditions Interview Sheet for second judgment Use the following flowchart to judge whether the restriction applies If the restriction might apply a third judgment using check tools is required Yes Check both the assembly source and C source Checking the assembly source C source Is amul or mulu instruction used in the source code Yes Go to third judgment using check tools Restriction does not apply Be sure to also check the C source according to the procedure following in this flowchart If the restriction is not judged to apply to either assembly or C the restriction does not apply to your code Use the check tool for hex objects When executing the check tool specify the Missalign y option Be sure to also check the C source according to the procedure following in this flowchart Note 1 When using the CA850 The restriction might apply if either the following conditions is satisfied No Restriction does not apply 1 pragma pack 1 or pragma pack 2 is specified in the source code 2 Xpack 1 or Xpack 2 is specified as a compiler option Note 2 When using a GHS compiler The restriction might apply if either the following conditions is satisfied 1 pragma pack 1 or pragma pack 2 is specified in the sou
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