Transcript chapter 7
00H SFRs for IO Control 18H-19H SP 1AH-7FH AND 100HAFFH Register File 232B and 256B additional RAM 0200H 1FFDH External Memory 1FFEH P3 1FFFH P4 2000H Lower Table of Interrupt Vectors 2014H Future Expansion Reserve 2018H Config Byte Future Expansion Reserve 2020H-202FH Security Key ROM/EPROM 2030H-203FH Upper Table of Interrupt Vectors 2040H-205DH Peripheral transaction Server Vectors Future Expansion Reserve 2080H ROM/EPROM Prog./Data Internal/Ext 6000H-0FFFFH External Prog/Data/IO Memory ROM/RAM Initializing CLR - Clear Word CLRB - Clear Byte CLRC - Clear Carry Flag CLRVT - Clear Overflow Trap SETC - Set Carry Flag 2.4.2 Data transfer BMOVE - Block Move (80c196KB only) LD - Load Word LDB - Load Byte LDBSE - Load Integer with Short-Integer LDBZE - Load Word with Byte ST - Store Word STB - Store Byte Stack operations POP - Pop Word POPA - Pop All (80c196KB only) POPF - Pop Flags PUSH - Push Word PUSHA - Push All (80c196KB only) PUSHF - Push Flags Arithmetic operations ADD - Add Words ADDB - Add Bytes ADDC - Add Words with Carry ADDCB - Add Bytes with Carry DEC - Decrement Word DECB - Decrement Byte DIV - Divide Integers (signed) DIVB - Divide Short Integers (signed) DIVU - Divide Words (unsigned) DIVUB - Divide Bytes (unsigned) EXT - Sign Extend Integer into Long-Integer EXTB - Sign Extend Short-Integer into Integer INC - Increment Word INCB - Increment Byte MUL - Multiply Integers (signed) MULB - Multiply Short Integers (signed) MULU - Multiply Words (unsigned MULUB - Multiply Bytes (unsigned NEG - Negate Integer NEGB - Negate Short-Integer NORML - Normalize Long-Integer SUB - Subtract Words SUBB - Subtract Bytes SUBC - Subtract Words With Borrow SUBCB - Subtract Words With Borrow Logical operations AND - Bitwise Logical AND Words ANDB - Bitwise Logical AND Bytes NOT - Complement Word NOTB - Complement Byte OR - Bitwise Logical OR Words ORB - Bitwise Logical OR Bytes XOR - Bitwise Logical XOR Words XORB - Bitwise Logical XOR Bytes Shifts SHL - Left Shift Word SHLB - Left Shift Byte SHLL - Left Shift Double-Word SHR - Logical Right Shift Word SHRA - Arithmetic Right Shift Word SHRAB - Arithmetic Right Shift Byte SHRAL - Arithmetic Right Shift Double-Word SHRB - Logical Right Shift Byte SHRL - Logical Right Shift Double-Word Comparisons CMP - Compare Words CMPB - Compare Bytes CMPL - Compare Long (80c196KB only) Unconditional jumps and calls BR - Branch Indirect LCALL - Long Call LJMP - Long Jump RET - Return from Subroutine SCALL - Short Call SJMP - Short Jump Conditional jumps DJNZ - Decrement and Jump if not Zero DJNZW - Decrement and Jump if Not Zero Word (80c196KB only) JBC - Jump if Bit Clear JBS - Jump if Bit Set JC - Jump if Carry JE - Jump if Equal JGE - Jump if Greater or Equal (signed) JGT - Jump if Greater than (signed) JH - Jump if Higher (unsigned) JLE - Jump if Less or Equal (signed) JLT - Jump if Less than (signed) JNC - Jump if No Carry JNE - Jump if Not Equal JNH - Jump if Not Higher (unsigned) JNST - Jump if No Sticky bit JNV - Jump if No Overflow JNVT - Jump if No Overflow Trap JST - Jump if Sticky bit JV - Jump if Overflow JVT - Jump if Overflow Trap Control DI - Disable Interrupts EI - Enable Interrupts IDLPD - Idle / Powerdown (80c196KB only) NOP - No Operation RST - Reset System SKIP - Two-byte NOP TRAP - Software Trap AX, BX, CX, DX are 16-bit registers. AL, AH are the lower byte and the higher byte of AX respectively. BL, BH are the lower byte and the higher byte of BX respectively. CL, CH are the lower byte and the higher byte of CX respectively. DL, DH are the lower byte and the higher byte of DX respectively. These are the same as the names for the general data registers used in the 8086. It is important to understand that in the 80c196 these are not dedicated registers, but merely the symbolic name assigned by the programmer to four words within the on-chip 232 general registers. 1. Implicit Addressing Modes: Examples: 1. SETC 2. POPF 3. PUSHF 2. Direct Addressing Mode: (Register Direct or Page 0 Address Direct): The register-direct mode is used to directly access a register, selected by an 8-bit field within the instruction. The register address must conform to the operand's type alignment rules. Examples LD BD, BS ADD WD, WS!, WS2 ADD AX,BX,CX INCB CL ; (AX)16 <-- (BX)16 + (CX)16 ; (CL)8 <-- (CL)8 + 1 3. Immediate Addressing Mode: This addressing mode allows an operand to taken directly from a field in the instruction. For operations on bytes this field is 8-bit wide, for operations on words it is 16-bit wide. Examples: LD WD, #3000H ADD WD, WS1, #data16 ADD WD, #data16 ADD AX,#340 PUSH #1234H ; (AX)16 <-- (AX)16 + 340 ; (SP)16 <-- (SP)16 - 2 ; ((SP)16)16 <-- 1234H DIVB AX,#10 ; (AL)8 <-- (AX)16 / 10 ; (AH)8 <-- (AX)16 % 10 4. Indirect Addressing Modes: a) Without auto post increment of the pointer Examples: ADD WD, WS1, [WS2] LD BX,[AX] ; (BX)16 <-- ((AX)16)16 ADDB AL,BL,[CX] ; (AL)8 <-- (BL)8 + ((CX)16)8 POP [AX] ; ((AX)16)16 <-- ((SP)16)16 ; (SP)16 <-- (SP)16 + 2 With auto post increment of the pointer, Examples: ADD WD, WS1, [WS2]+ LD AX,[BX]+ ; (AX)16 <-- ((BX)16)16 ; (BX)16 <-- (BX)16 + 2 ADDB AL,BL,[CX]+ ; (AL)8 <-- (BL)8 + ((CX)16)8 ; (CX)16 <-- (CX)16 + 2 PUSH [AX]+ ; (SP)16 <-- (SP)16 - 2 ; ((SP)16)16 <-- ((AX)16)16 ; (AX)16 <-- (AX)16 + 2 C) Indexed short In this addressing mode an 8-bit field in the instruction selects a word register which contains an address. A second 8-bit field in the instruction stream (displacement) is sign-extended and summed with the register value to form the address of the operand. Since the displacement is sign-extended, the effective address can be up to 128 bytes before the address in the register, or up to 127 bytes after it. Examples LD AX,12[BX] ; (AX)16 <-- ((BX)16 + 12)16 MULB AX,BL,3[CX] ; (AX)16 <-- (BL)8 * ((CX)16 + 3)8 D) Indexed long This addressing mode is like short indexed addressing except that the displacement is a 16-bit field taken from the instruction stream to form the address of the operand. No sign extension is necessary. Examples AND AX,BX,TABLE[CX] ; (AX)16 <-- (BX)16 . (TABLE16 + (CX)16)16 ST AX,TABLE[BX] ; (AX)16 <-- (TABLE16 + (BX)16)16 ADDB AL,BL,TABLE[CX] ; (AL)8 <-- (BL)8 + (TABLE16 + (CX)16)8 Examples: 1. ST XD, YS 2. LD 3. PUSH 4. POP Examples: 1. CLRB XD 2. CLRW XD 3. CLRLD XD A byte or word can be extended to a word or a long word by sign bit extension. Examples: 1. EXTB XD 2. EXTW XD Similarly, normalization of a byte into a word or a long word or a word into a long word can also be done. Normalization is simply putting 0s at the higher bytes. Logical Operations: 1. NOTB XD 2. NOTW XD 3. NOTLD XD EI => Enable Interrupt (PSW.9) DI => Disable Interrupt CLRC => Clear Carry Flag SETC => set Carry Flag CLRVT => Clear VT Flag V: The oVerflow flag is set to indicate that the operation generated a result which is outside the range for the destination data type. For the left shift operations the V flag will be set if the most significant bit changes at any time during the shift. VT : The oVerflow Trap flag is set when the V flag is set, but is only cleared by the CLRVT, JVT and JNVT instructions. The operation of the VT flag allows testing for a possible overflow condition at the end of a sequence of related arithmetic operations. This is generally more efficient than testing the VT flag after each instruction. C : The Carry flag is set to indicate the state of the arithmetic carry from the most significant bit of the ALU for arithmetic operations, or the state of the last bit shifted out of an operand for shift operations. Arithmetic borrow after a subtract operation is the complement of the C flag (i.e. if the operation generated a borrow the C flag is cleared). X : Reserved. Should always be cleared when writing to the PSW (cf. POPF instruction). I : The global Interrupt disable bit disables all interrupts except NMI when cleared. Z : The Zero flag is set to indicate that the operation generated a result equal to zero. For the add-with-carry (ADDC) and subtract-with-borrow (SUBB) operations the Z flag is cleared if the result is not zero, but is never set. These two instructions are normally used on conjunction with the ADD and SUB instructions to perform multiple precision arithmetic. Theoperation of the Z flag for these operations leaves it indicating the proper result for the entire multiple precision calculation. N : The Negative flag is set to indicate that the operation generated a negative result. The N flag will be in the algebraically correct state even if an overflow occurs. For shift operations the N flag will be set to the same value as the most significant bit of the result. This is true even if the shift count is 0. ST : The STicky bit flag is set to indicate that during a shift a 1 has first been shifted into the C flag, and then shifted out. The ST flag is undefined after a multiply operation. The ST flag can be used along with the C flag to control rounding after a right shift. Consider multiplying to 8-bit quantities and then scaling the result down to 12 bits : MULUB AX,CL,DL ; AX <-- CL*DL SHR AX,#4 ; shift right 4 places If the C flag is set after the shift, it indicates that the bits shifted off the end of the operand were greater-than or equal-to half the LSB of the result. Without the ST flag, the rounding decision must be made on the basis of the C flag alone.