PIC18F6621-I/PT Microchip Technology Inc., PIC18F6621-I/PT Datasheet - Page 308

• Manufacturer Part Number: PIC18F6621-I/PT
• Description: 64 PIN, 64 KB FLASH, 3840 RAM, 52 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F6621-I/PT

• A/d Inputs: 12-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 10 MIPS
• Eeprom Memory: 1024 Bytes
• Input Output: 54
• Interface: I2C/SPI/UART/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 64-pin TQFP
• Programmable Memory: 64K Bytes
• Ram Size: 3.8K Bytes
• Speed: 40 MHz
• Timers: 2-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC18F6525/6621/8525/8621
RETFIE
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example:
DS39612B-page 306
Q Cycle Activity:
After Interrupt
operation
Decode
PC
W
BSR
STATUS
GIE/GIEH, PEIE/GIEL
No
Q1
operation
operation
Return from Interrupt
[ label ]
s ∈ [0,1]
(TOS) → PC;
1 → GIE/GIEH or PEIE/GIEL
if s = 1
(WS) → W;
(STATUSS) → STATUS;
(BSRS) → BSR;
PCLATU, PCLATH are unchanged
GIE/GIEH, PEIE/GIEL.
Return from interrupt. Stack is popped
and Top-of-Stack (TOS) is loaded into
the PC. Interrupts are enabled by
setting either the high or low priority
global interrupt enable bit. If ‘s’ = 1, the
contents of the shadow registers WS,
STATUSS and BSRS are loaded into
their corresponding registers, W,
STATUS and BSR. If ‘s’ = 0, no update
of these registers occurs (default).
1
2
RETFIE
0000
No
No
Q2
RETFIE [s]
1
0000
operation
operation
=
=
=
=
=
No
No
Q3
TOS
WS
BSRS
STATUSS
1
0001
Set GIEH or
from stack
operation
Pop PC
GIEL
No
Q4
000s
RETLW
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example:
TABLE
Q Cycle Activity:
:
:
:
CALL TABLE ; W contains table
ADDWF PCL
RETLW k0
RETLW k1
RETLW kn
Before Instruction
After Instruction
operation
Decode
W
W
No
Q1
; offset value
; W now has
; table value
; W = offset
; Begin table
;
; End of table
=
=
operation
Return Literal to W
[ label ]
0 ≤ k ≤ 255
k → W;
(TOS) → PC;
PCLATU, PCLATH are unchanged
None
W is loaded with the eight-bit literal ‘k’.
The program counter is loaded from the
top of the stack (the return address).
The high address latch (PCLATH)
remains unchanged.
1
2
literal ‘k’
Read
0000
No
Q2
0x07
value of kn
 2005 Microchip Technology Inc.
RETLW k
1100
operation
Process
Data
No
Q3
kkkk
from stack,
Write to W
operation
Pop PC
No
Q4
kkkk