 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
HT82K75RE Datasheet(PDF) 8 Page - Holtek Semiconductor Inc |
|
||||||||||||||||||||||||||||||
HT82K75RE Datasheet(HTML) 8 Page - Holtek Semiconductor Inc |
|
|
8 / 66 page  HT82M75R/HT82M75RE HT82K75R/HT82K75RE Rev. 1.10 8 June 11, 2010 When executing instructions requiring jumps to non-consecutive addresses such as a jump instruction, a subroutine call, interrupt or reset, etc., the microcontroller manages program control by loading the required address into the Program Counter. For condi- tional skip instructions, once the condition has been met, the next instruction, which has already been fetched during the present instruction execution, is dis- carded and a dummy cycle takes its place while the cor- rect instruction is obtained. The lower byte of the Program Counter, known as the Program Counter Low register or PCL, is available for program control and is a readable and writeable regis- ter. By transferring data directly into this register, a short program jump can be executed directly, however, as only this low byte is available for manipulation, the jumps are limited to the present page of memory, that is 256 locations. When such program jumps are executed it should also be noted that a dummy cycle will be in- serted. The lower byte of the Program Counter is fully accessi- ble under program control. Manipulating the PCL might cause program branching, so an extra cycle is needed to pre-fetch. Further information on the PCL register can be found in the Special Function Register section. Stack This is a special part of the memory which is used to save the contents of the Program Counter only. The stack has 6 levels and is neither part of the data nor part of the program space, and is neither readable nor writeable. The activated level is indexed by the Stack Pointer, SP, and is neither readable nor writeable. At a subroutine call or interrupt acknowledge signal, the con- tents of the Program Counter are pushed onto the stack. At the end of a subroutine or an interrupt routine, sig- naled by a return instruction, RET or RETI, the Program Counter is restored to its previous value from the stack. After a device reset, the Stack Pointer will point to the top of the stack. If the stack is full and an enabled interrupt takes place, the interrupt request flag will be recorded but the ac- knowledge signal will be inhibited. When the Stack Pointer is decremented, by RET or RETI, the interrupt will be serviced. This feature prevents stack overflow al- lowing the programmer to use the structure more easily. However, when the stack is full, a CALL subroutine in- struction can still be executed which will result in a stack overflow. Precautions should be taken to avoid such cases which might cause unpredictable program branching. Mode Program Counter Bits b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0 Initial Reset 0 00000000000 SPI Interrupt 0 00000000100 Timer/Event Counter Overflow 0 00000001000 External interrupt 0 00000001100 Skip Program Counter + 2 Loading PCL PC11 PC10 PC9 PC8 @7 @6 @5 @4 @3 @2 @1 @0 Jump, Call Branch #11 #10 #9 #8 #7 #6 #5 #4 #3 #2 #1 #0 Return from Subroutine S11 S10 S9 S8 S7 S6 S5 S4 S3 S2 S1 S0 Program Counter Note: PC11~PC8: Current Program Counter bits @7~@0: PCL bits #11~#0: Instruction code address bits S11~S0: Stack register bits P r o g r a m C o u n t e r S t a c k L e v e l 1 S t a c k L e v e l 2 S t a c k L e v e l 3 S t a c k L e v e l 6 P r o g r a m M e m o r y T o p o f S t a c k S t a c k P o i n t e r B o t t o m o f S t a c k |
Similar Part No. - HT82K75RE |
|
Similar Description - HT82K75RE |
|
|
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
