; A = A + $01 + carry,如果结果是0,0标记设置 SBC #$80 ; 借位减 ; A = A - $80 - (1 - carry),如果结果是0,0标记设置 CLC ; 清除状态寄存器的进位标记,通常这个在ADC之前被使用 SEC ; 在状态寄存器设置进位标记,通常在SBC之前完成 INC $0100 ; 增加地址在$0100的值,如果结果是0,0标记被...
| Zero Page,X | SBC Oper,X | F5 | 2 | 4 | | Absolute | SBC Oper | ED | 3 | 4 | | Absolute,X | SBC Oper,X | FD | 3 | 4* | | Absolute,Y | SBC Oper,Y | F9 | 3 | 4* | | (Indirect,X) | SBC (Oper,X) | E1 | 2 | 6 | ...
SBC #{imm} = SBC #{imm} + NOP note to ANC: this command performs an AND operation only, but bit 7 is put into the carry, as if the ASL/ROL would have been executed. note to ARR: part of this command are some ADC mechanisms. following effects appear after AND but before ROR...
0xE000 ~ 0xFFFF -> 8KBytes EEPROM -> AT28C64 实际上串口和I/O芯片用不到那么大的地址空间,这么分配虽然有点浪费,但这样的好处是不用特别做地址编码,只要用A13/A14/A15几个引脚再加上74HC00就可以完成address decode,简单方便。 8KB的EEPROM和32KB的SRAM应该足够使用了,应该没有人的代码会超过32KB吧。 ...
但是,SBC这个指令一般叫做“带借位减法”,因为如果状态寄存器P中的“进位”位的值是1, 那么要在结果上再减1,放回A寄存器。也就是说,SBC执行的是3个数的相减:A寄存器 - 操作数 - P寄存器的进位位例:A寄存器原有值为$0060,P寄存器的进位位是1。执行下列指令后,A寄存器的内容变成$000F。A: 0060 SBC ...
(The two 6522's and a 6551 are what Daryl Rictor's SBC-2 board has.) The ISR first checks with the #1 6522 VIA. If that one is not the one that caused the interrupt, check the second VIA. If that one didn't either, the assumption is that the ACIA did it, since there's ...
is due to the CMP command, which is executedinstead of the real SBC.ARR $6B This instruction first performs an ANDbetween the accumulator and the immediateparameter, then it shifts the accumulator tothe right. However, this is not the whole...
Math and Logic commands (ADC, SBC, AND) Branching Commands (BEQ, JMP, BPL) 6502 Assembly doesn't really have variables. It just has places in RAM where you can put stuff. You can assign labels to these memory locations and they kind of act like variables, but these labels are effective...
*-JAM and STP are essentially the same command; they both halt the CPU.Note: Illegal mnemonics are only available if the 6502i option is specified in the --cpu commandline or .cpu directive.Pseudo-OpsFollowing is the detail of each of the 6502.Net pseudo operations, or psuedo-ops. A ...
DB 00美元、00美元、00美元、00美元、00美元 dectobin:中国人民解放军 STA dectobinrtn2 + 1 中国人民解放军 STA dectobinrtn1 + 1 # LDX 04美元;65535 dectobin02:;* 10 = 2 *(* 2 * 2 +)中国人民解放军美国证券交易委员会 SBC # 30美元 STA decbindata,X CPX # 00美元贝克dectobin04 DEX JMP ...