 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
UPD62AMC Datasheet(PDF) 9 Page - NEC |
|
||||||||||||||||||||||||||||||
UPD62AMC Datasheet(HTML) 9 Page - NEC |
|
|
9 / 62 page  9 µPD62A Data Sheet U14474EJ1V0DS00 2. INTERNAL CPU FUNCTIONS 2.1 Program Counter (PC): 10 Bits This is a binary counter that holds the address information of the program memory. Figure 2-1. Program Counter Configuration PC9 PC0 PC8 PC7 PC6 PC5 PC4 PC3 PC2 PC1 PC The program counter contains the address of the instruction that should be executed next. Normally, the counter contents are automatically incremented in accordance with the instruction length (byte count) each time an instruction is executed. However, when executing JUMP instructions (JMP, JC, JNC, JF, JNF), the program counter contains the jump destination address written in the operand. When executing the subroutine call instruction (CALL), the call destination address written in the operand is entered in the PC after the PC contents at the time are saved in the address stack register (ASR). If the return instruction (RET) is executed after the CALL instruction is executed, the address saved in the ASR is restored to the PC. When reset, the value of the program counter becomes “000H”. 2.2 Stack Pointer (SP): 1 Bit This is a 1-bit register which holds the status of the address stack register. The stack pointer contents are incremented when the call instruction (CALL) is executed; they are decremented when the return instruction (RET) is executed. When reset, the stack pointer contents are cleared to 0. When the stack pointer overflows (stack level 2 or more) or underflows, the CPU is hung up and a system reset signal is generated, and the PC becomes “000H”. As no instruction is available to set a value directly for the stack pointer, it is not possible to operate the pointer by means of a program. 2.3 Address Stack Register (ASR (RF)): 10 Bits The address stack register saves the return address of the program after a subroutine call instruction is executed. The low-order 8 bits are configured as RAM that is also used as the data memory RF. The register holds the ASR value even after RET is executed. When reset, it holds the previous data (undefined on power application). Caution If RF is accessed as data memory, the high-order 2 bits of the ASR become undefined. Figure 2-2. Address Stack Register Configuration ASR9 ASR8 ASR7 ASR6 ASR5 ASR4 ASR3 ASR2 ASR1 ASR0 ASR RF |
Similar Part No. - UPD62AMC |
|
Similar Description - UPD62AMC |
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.NET |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
