SLAA140A February   2002  – August 2018 MSP430BT5190 , MSP430BT5190 , MSP430F1101 , MSP430F1101 , MSP430F1101A , MSP430F1101A , MSP430F1111A , MSP430F1111A , MSP430F112 , MSP430F112 , MSP430F1121 , MSP430F1121 , MSP430F1121A , MSP430F1121A , MSP430F1122 , MSP430F1122 , MSP430F1132 , MSP430F1132 , MSP430F122 , MSP430F122 , MSP430F1222 , MSP430F1222 , MSP430F123 , MSP430F123 , MSP430F1232 , MSP430F1232 , MSP430F133 , MSP430F133 , MSP430F135 , MSP430F135 , MSP430F147 , MSP430F147 , MSP430F1471 , MSP430F1471 , MSP430F148 , MSP430F148 , MSP430F1481 , MSP430F1481 , MSP430F149 , MSP430F149 , MSP430F1491 , MSP430F1491 , MSP430F155 , MSP430F155 , MSP430F156 , MSP430F156 , MSP430F157 , MSP430F157 , MSP430F1610 , MSP430F1610 , MSP430F1611 , MSP430F1611 , MSP430F1612 , MSP430F1612 , MSP430F167 , MSP430F167 , MSP430F168 , MSP430F168 , MSP430F169 , MSP430F169 , MSP430F2001 , MSP430F2001 , MSP430F2002 , MSP430F2002 , MSP430F2003 , MSP430F2003 , MSP430F2011 , MSP430F2011 , MSP430F2012 , MSP430F2012 , MSP430F2013 , MSP430F2013 , MSP430F2013-EP , MSP430F2013-EP , MSP430F2101 , MSP430F2101 , MSP430F2111 , MSP430F2111 , MSP430F2112 , MSP430F2112 , MSP430F2121 , MSP430F2121 , MSP430F2122 , MSP430F2122 , MSP430F2131 , MSP430F2131 , MSP430F2132 , MSP430F2132 , MSP430F2232 , MSP430F2232 , MSP430F2234 , MSP430F2234 , MSP430F2252 , MSP430F2252 , MSP430F2252-Q1 , MSP430F2252-Q1 , MSP430F2254 , MSP430F2254 , MSP430F2272 , MSP430F2272 , MSP430F2272-Q1 , MSP430F2272-Q1 , MSP430F233 , MSP430F233 , MSP430F2330 , MSP430F2330 , MSP430F235 , MSP430F235 , MSP430F2350 , MSP430F2350 , MSP430F2370 , MSP430F2370 , MSP430F2410 , MSP430F2410 , MSP430F2416 , MSP430F2416 , MSP430F2417 , MSP430F2417 , MSP430F2418 , MSP430F2418 , MSP430F2419 , MSP430F2419 , MSP430F247 , MSP430F247 , MSP430F2471 , MSP430F2471 , MSP430F248 , MSP430F248 , MSP430F2481 , MSP430F2481 , MSP430F249 , MSP430F249 , MSP430F2491 , MSP430F2491 , MSP430F2616 , MSP430F2616 , MSP430F2617 , MSP430F2617 , MSP430F2618 , MSP430F2618 , MSP430F2619 , MSP430F2619 , MSP430F412 , MSP430F412 , MSP430F413 , MSP430F413 , MSP430F4132 , MSP430F4132 , MSP430F415 , MSP430F415 , MSP430F4152 , MSP430F4152 , MSP430F417 , MSP430F417 , MSP430F423 , MSP430F423 , MSP430F423A , MSP430F423A , MSP430F425 , MSP430F425 , MSP430F4250 , MSP430F4250 , MSP430F425A , MSP430F425A , MSP430F4260 , MSP430F4260 , MSP430F427 , MSP430F427 , MSP430F4270 , MSP430F4270 , MSP430F427A , MSP430F427A , MSP430F435 , MSP430F435 , MSP430F4351 , MSP430F4351 , MSP430F436 , MSP430F436 , MSP430F4361 , MSP430F4361 , MSP430F437 , MSP430F437 , MSP430F4371 , MSP430F4371 , MSP430F438 , MSP430F438 , MSP430F439 , MSP430F439 , MSP430F447 , MSP430F447 , MSP430F448 , MSP430F448 , MSP430F4481 , MSP430F4481 , MSP430F449 , MSP430F449 , MSP430F4491 , MSP430F4491 , MSP430F4616 , MSP430F4616 , MSP430F46161 , MSP430F46161 , MSP430F4617 , MSP430F4617 , MSP430F46171 , MSP430F46171 , MSP430F4618 , MSP430F4618 , MSP430F46181 , MSP430F46181 , MSP430F4619 , MSP430F4619 , MSP430F46191 , MSP430F46191 , MSP430F47126 , MSP430F47126 , MSP430F47127 , MSP430F47127 , MSP430F47163 , MSP430F47163 , MSP430F47166 , MSP430F47166 , MSP430F47167 , MSP430F47167 , MSP430F47173 , MSP430F47173 , MSP430F47176 , MSP430F47176 , MSP430F47177 , MSP430F47177 , MSP430F47183 , MSP430F47183 , MSP430F47186 , MSP430F47186 , MSP430F47187 , MSP430F47187 , MSP430F47193 , MSP430F47193 , MSP430F47196 , MSP430F47196 , MSP430F47197 , MSP430F47197 , MSP430F477 , MSP430F477 , MSP430F478 , MSP430F478 , MSP430F4783 , MSP430F4783 , MSP430F4784 , MSP430F4784 , MSP430F479 , MSP430F479 , MSP430F4793 , MSP430F4793 , MSP430F4794 , MSP430F4794 , MSP430F5304 , MSP430F5304 , MSP430F5308 , MSP430F5308 , MSP430F5309 , MSP430F5309 , MSP430F5310 , MSP430F5310 , MSP430F5324 , MSP430F5324 , MSP430F5325 , MSP430F5325 , MSP430F5326 , MSP430F5326 , MSP430F5327 , MSP430F5327 , MSP430F5328 , MSP430F5328 , MSP430F5329 , MSP430F5329 , MSP430F5333 , MSP430F5333 , MSP430F5336 , MSP430F5336 , MSP430F5338 , MSP430F5338 , MSP430F5340 , MSP430F5340 , MSP430F5341 , MSP430F5341 , MSP430F5342 , MSP430F5342 , MSP430F5418 , MSP430F5418 , MSP430F5418A , MSP430F5418A , MSP430F5419 , MSP430F5419 , MSP430F5419A , MSP430F5419A , MSP430F5435 , MSP430F5435 , MSP430F5435A , MSP430F5435A , MSP430F5436 , MSP430F5436 , MSP430F5436A , MSP430F5436A , MSP430F5437 , MSP430F5437 , MSP430F5437A , MSP430F5437A , MSP430F5438 , MSP430F5438 , MSP430F5500 , MSP430F5500 , MSP430F5501 , MSP430F5501 , MSP430F5502 , MSP430F5502 , MSP430F5503 , MSP430F5503 , MSP430F5504 , MSP430F5504 , MSP430F5505 , MSP430F5505 , MSP430F5506 , MSP430F5506 , MSP430F5507 , MSP430F5507 , MSP430F5508 , MSP430F5508 , MSP430F5509 , MSP430F5509 , MSP430F5510 , MSP430F5510 , MSP430F5513 , MSP430F5513 , MSP430F5514 , MSP430F5514 , MSP430F5515 , MSP430F5515 , MSP430F5517 , MSP430F5517 , MSP430F5519 , MSP430F5519 , MSP430F5521 , MSP430F5521 , MSP430F5522 , MSP430F5522 , MSP430F5524 , MSP430F5524 , MSP430F5525 , MSP430F5525 , MSP430F5526 , MSP430F5526 , MSP430F5527 , MSP430F5527 , MSP430F5529 , MSP430F5529 , MSP430F5630 , MSP430F5630 , MSP430F5631 , MSP430F5631 , MSP430F5632 , MSP430F5632 , MSP430F5633 , MSP430F5633 , MSP430F5634 , MSP430F5634 , MSP430F5635 , MSP430F5635 , MSP430F5636 , MSP430F5636 , MSP430F5637 , MSP430F5637 , MSP430F5638 , MSP430F5638 , MSP430F6433 , MSP430F6433 , MSP430F6435 , MSP430F6435 , MSP430F6436 , MSP430F6436 , MSP430F6438 , MSP430F6438 , MSP430F6630 , MSP430F6630 , MSP430F6631 , MSP430F6631 , MSP430F6632 , MSP430F6632 , MSP430F6633 , MSP430F6633 , MSP430F6634 , MSP430F6634 , MSP430F6635 , MSP430F6635 , MSP430F6636 , MSP430F6636 , MSP430F6637 , MSP430F6637 , MSP430F6638 , MSP430F6638 , MSP430FE423 , MSP430FE423 , MSP430FE4232 , MSP430FE4232 , MSP430FE423A , MSP430FE423A , MSP430FE4242 , MSP430FE4242 , MSP430FE425 , MSP430FE425 , MSP430FE4252 , MSP430FE4252 , MSP430FE425A , MSP430FE425A , MSP430FE427 , MSP430FE427 , MSP430FE4272 , MSP430FE4272 , MSP430FE427A , MSP430FE427A , MSP430FG4250 , MSP430FG4250 , MSP430FG4260 , MSP430FG4260 , MSP430FG4270 , MSP430FG4270 , MSP430FG437 , MSP430FG437 , MSP430FG438 , MSP430FG438 , MSP430FG439 , MSP430FG439 , MSP430FG4616 , MSP430FG4616 , MSP430FG4617 , MSP430FG4617 , MSP430FG4618 , MSP430FG4618 , MSP430FG4619 , MSP430FG4619 , MSP430FG477 , MSP430FG477 , MSP430FG478 , MSP430FG478 , MSP430FG479 , MSP430FG479 , MSP430FG6425 , MSP430FG6425 , MSP430FG6426 , MSP430FG6426 , MSP430FG6625 , MSP430FG6625 , MSP430FG6626 , MSP430FG6626 , MSP430FW423 , MSP430FW423 , MSP430FW425 , MSP430FW425 , MSP430FW427 , MSP430FW427 , MSP430FW428 , MSP430FW428 , MSP430FW429 , MSP430FW429 , MSP430G2001 , MSP430G2001 , MSP430G2101 , MSP430G2101 , MSP430G2102 , MSP430G2102 , MSP430G2111 , MSP430G2111 , MSP430G2112 , MSP430G2112 , MSP430G2121 , MSP430G2121 , MSP430G2131 , MSP430G2131 , MSP430G2132 , MSP430G2132 , MSP430G2152 , MSP430G2152 , MSP430G2201 , MSP430G2201 , MSP430G2201-Q1 , MSP430G2201-Q1 , MSP430G2211 , MSP430G2211 , MSP430G2212 , MSP430G2212 , MSP430G2221 , MSP430G2221 , MSP430G2231-Q1 , MSP430G2231-Q1 , MSP430G2232 , MSP430G2232 , MSP430G2252 , MSP430G2252 , MSP430G2302 , MSP430G2302 , MSP430G2312 , MSP430G2312 , MSP430G2332 , MSP430G2332 , MSP430G2352 , MSP430G2352 , MSP430G2402 , MSP430G2402 , MSP430G2432 , MSP430G2432 , MSP430G2452 , MSP430G2452 , MSP430L092 , MSP430L092

 

  1.   Mixing C and Assembler With MSP430™ MCUs
    1.     Trademarks
    2. 1 Definition of the C-Compiler for Passing Variables Between Functions
      1. 1.1 Stack Frames and Parameter Passing
      2. 1.2 Calling Convention – Register Use With the IAR C-Compiler
      3. 1.3 Calling Convention – Register Use With the CCS C-Compiler
      4. 1.4 Interrupt Functions
    3. 2 Requirements of Assembler Routines to Support Calls From C
      1. 2.1 Local Storage Allocation
      2. 2.2 Interrupt Functions
      3. 2.3 Define Interrupt Vectors
    4. 3 Combining C and Assembler Functions
      1. 3.1 General Basics
      2. 3.2 Call Assembler Functions Without Parameters to Pass
      3. 3.3 Call Assembler Functions With Parameters to Pass
      4. 3.4 Define an Interrupt Service Routine in Assembler
      5. 3.5 Define an Interrupt Service Routine for Special Interrupts
      6. 3.6 Call C Functions from Assembler
      7. 3.7 Exit Low-Power Mode While in the Interrupt Service Routine
  2.   Revision History

1.2 Calling Convention – Register Use With the IAR C-Compiler

The compiler uses two groups of processor registers.

  • The scratch registers R12 to R15 are used for parameter passing and are not normally preserved across the call. If R8 to R11 are used to hold a 64-bit parameter, these registers are also not preserved.
  • The other general-purpose registers, R4 to R11, are mainly used for register variables and temporary results and must be preserved across a call. Within C this is handled automatically.

NOTE

The –ur45 or --lock_r4 and --lock_r5 option prevents the compiler from using registers R4 and R5.

Table 1. Location of Passed Parameters

Argument 8-Bit or 16-Bit Type 32-Bit Type 64-Bit Type Struct or Union
4th (z) R15 On the stack On the stack On the stack
3th (y) R14 On the stack On the stack On the stack
2nd (x) R13 R15:R14 R11:R10:R8:R8 On the stack
1st (w) R12 R12:R13 R15:R14:R13:R12 On the stack
Result R12 R12:R13 R15:R14:R13:R12 On the stack

NOTE

IAR also support an older calling convention (version 1). For details, refer to the IAR C Compiler documentation