CPU Registers
4-12
16-Bit MSP430X CPU
4.3.5
The General Purpose Registers R4 to R15
The twelve CPU registers R4 to R15, contain 8-bit, 16-bit, or 20-bit values. Any
byte-write to a CPU register clears bits 19:8. Any word-write to a register clears
bits 19:16. The only exception is the SXT instruction. The SXT instruction
extends the sign through the complete 20-bit register.
The following figures show the handling of byte, word and address-word data.
Note the reset of the leading MSBs, if a register is the destination of a byte or
word instruction.
Figure 4−10 shows byte handling (8-bit data, .B suffix). The handling is shown
for a source register and a destination memory byte and for a source memory
byte and a destination register.
Figure 4−10. Register-Byte/Byte-Register Operation
Unused
High Byte
Low Byte
Register-Byte Operation
High Byte
Low Byte
Byte-Register Operation
Register
Memory
Register
Memory
Operation
Memory
Operation
0
Register
Un-
used
Unused
Un-
used
0
19 16 15
0
19 16 15
0
8 7
8 7
Содержание MSP430x4xx Family
Страница 1: ...MSP430x4xx Family 2007 Mixed Signal Products User s Guide SLAU056G ...
Страница 2: ......
Страница 6: ...vi ...
Страница 114: ...3 76 RISC 16 Bit CPU ...
Страница 304: ...5 20 FLL Clock Module ...
Страница 340: ...7 8 Supply Voltage Supervisor ...
Страница 348: ...8 8 16 Bit Hardware Multiplier ...
Страница 372: ...9 24 32 Bit Hardware Multiplier ...
Страница 400: ...10 28 DMA Controller ...
Страница 428: ...13 10 Basic Timer1 ...
Страница 466: ...15 24 Timer_A ...
Страница 522: ...17 30 USART Peripheral Interface UART Mode ...
Страница 544: ...18 22 USART Peripheral Interface SPI Mode ...
Страница 672: ...23 12 Comparator_A ...
Страница 692: ...24 20 LCD Controller ...
Страница 746: ...26 28 ADC12 ...