TSC80251 TEMIC [TEMIC Semiconductors], TSC80251 Datasheet - Page 121

• Manufacturer Part Number: TSC80251
• Manufacturer: TEMIC [TEMIC Semiconductors]

TSC80251
ECALL <dest>
Function:
Extended call
Description:
Calls a subroutine located at the specified address. The instruction adds four to the program counter to generate the
address of the next instruction and then PUSHes the 24–bit result onto the stack (high byte first), incrementing the stack
pointer by three. The 8 bits of the high word and the 16 bits of the low word of the PC are then loaded, respectively,
with the second, third and fourth bytes of the ECALL instruction. Program execution continues with the instruction
at this address. The subroutine may therefore begin anywhere in the full 16–Mbyte memory space.
Example :
The stack pointer contains 07h and the label ”SUBRTN” is assigned to program memory location 123456h. After
executing the instruction ECALL SUBRTN at location 054321h, SP contains 0Ah; on–chip RAM locations 08h, 09h
and 0Ah contain 05h, 43h and 21h, respectively; and the PC contains 123456h.
ECALL addr24
[Encoding]
ECALL @DRk
[Encoding]
5.76
FLAGS :
Hex Code in:
Binary Mode = [A5][Encoding]
Source Mode = [Encoding]
1001
1001
CY
_
1010
1001
AC
_
addr23- addr16
uuuu
OV
addr15-addr8
_
Operation:
ECALL
(PC)
(SP)
((SP))
(SP)
((SP))
(SP)
((SP))
(PC)
(SP) + 1
(SP) + 1
(SP) + 1
(PC) + 4
(addr.23:0)
(PC.15:8)
(PC.7:0)
(PC.23:16)
addr7-addr0
N
_
Rev. C – May 7, 1999
Z
_