Personal Equipment IC
 
   
 
Q1 : 

By "JINZ Port-E" of Port-E = 0xFF or "JDNZ Port-E" of Port-E = 0x00, 
Port-F is not changed.
Are these only case that Port-F is not affected by Port-E carry or borrow?

Q2 : 

Please explain about the STKPTR operation.

Q3 : 

How to setup the unused general I/O to avoid current consumption?

Q4 : 

How to archive Indirect Jump in NEW CPU series?

Q5 : 

How many cycles will TBRD instruction takes?



  Answer
Q1 :  

By "JINZ Port-E" of Port-E = 0xFF or "JDNZ Port-E" of Port-E = 0x00, 
Port-F is not changed.
Are these only case that Port-F is not affected by Port-E carry or borrow?

 

The multi-byte address carry/borrow is affected by the following instructions.
(1) ADD r,A
(2) ADC r,A
(3) SUB r,A
(4) SUBB r,A
(5) INC r
(6) DEC r
(7) JINZ r,addr
(8) JDNZ r,addr
(Note: 1. The multi-byte address means PCH:PCM:PCL 
                                                                         TABPTRH:TABPTRM:TABPTRL 
                                                                         PORTF:PORTE
                                                                         BSR1:FSR1 
               But LCDARH:LCDARL and BSR:FSR0 can NOT carry into/borrow from high byte 
           2. The "r" include of PCL,TABPTRL,PORTE and FSR1
               But if "r=TABPTRM" or "r= PCM", the carry into/borrow from high byte address will 
               NOT happen.
           3. We don't suggest to use the DINZ PCL,addr or DJNZ PCL,addr instruction )


Q2 :  

Please explain about the STKPTR operation.

 

The STKPTR value points at the high byte address of current level.
for example,
(1) When reset, the STKPTR=0x00
(2) After first CALL instruction, 
      0xFE==> store high byte PC address
      0xFF==> store low byte PC address

      STKPTR=0xFE

(3) After first RET instruction,
      High byte PC address restore from 0xFE
      Low byte PC address restore from 0xFF

      STKPTR=0X00


Q3 :  

How to setup the unused general I/O to avoid current consumption?

 

Please set the PortA with pull up enable and other Port to output LOW.
That will reduce the floating current.


Q4 :  

How to archive Indirect Jump in NEW CPU series?

 

You can archive Indirect jump by ADD PCL,A instruction
Carry bit of PCL will automatic carry into PCM:PCH .
The Instruction cycle of write to PC(program counter) takes TWO cycle.


Q5 :  

How many cycles will TBRD instruction takes?

 

TBRD instruction will take 2 cycles at first time, and then 1 cycle at following TBRD instructions. 
Ex1. TBRD 1,reg1 e Take 2 cycles
         TBRD 1,reg2 e Take 1 cycle
         TBRD 1,reg3 e Take 1 cycle
          ……………..
         TBRD 1,reg99 e Take 1 cycle
         NOP
         TBRD 1,reg100 e Take 2 cycles
         TBRD 1,reg101 e Take 1 cycle

Ex2. MOV A,#10
        RPT ACC
        TBRD 1,INDF1 e Repeat 10 times, total take 11 cycles