mc9s12xf512 Freescale Semiconductor, Inc, mc9s12xf512 Datasheet - Page 649

• Manufacturer Part Number: mc9s12xf512
• Description: S12x Microcontrollers 16-bit Automotive Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

14.8.2.5
This addressing mode is used to identify the position and size of a bit field for insertion or extraction. The
width and offset are coded in the lower byte of the source register 2, RS2. The content of the upper byte is
ignored. An offset of 0 denotes the right most position and a width of 0 denotes 1 bit. These instructions
are very useful to extract, insert, clear, set or toggle portions of a 16 bit word
14.8.2.6
The XGATE offers a number of additional instructions for flag manipulation, program flow control and
debugging:
14.8.3
Table 14-23
letter implies additional wait cycles if memories or peripherals are not accessible. Memories or peripherals
are not accessible if they are blocked by the S12X_CPU. In addition to this Peripherals are only accessible
every other XGATE cycle. Uppercase letters denote 16 bit operations. Lowercase letters denote 8 bit
operations. The XGATE is able to perform two bus or wait cycles per S12X_CPU cycle.
Freescale Semiconductor
1. SIF: Set a channel interrupt flag
2. SSEM: Test and set a hardware semaphore
3. CSEM: Clear a hardware semaphore
4. BRK: Software breakpoint
5. NOP: No Operation
6. RTS: Terminate the current thread
BFEXT
Cycle Notation
show the XGATE access detail notation. Each code letter equals one XGATE cycle. Each
Bit Field Operations
Special Instructions for DMA Usage
15
15
R3,R4,R5 ; R5: W4+1 bits with offset O4, will be extracted from R4 into R3
MC9S12XF - Family Reference Manual, Rev.1.19
Figure 14-26. Bit Field Addressing
Bit Field Insert
7
W4
W4=3, O4=2
5
4
3
3
2
O4
Bit Field Extract
0
0
0
RS2
RS1
RD
Chapter 14 XGATE (S12XGATEV3)
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