MC68EC000EI16 Freescale Semiconductor, MC68EC000EI16 Datasheet - Page 195

• Manufacturer Part Number: MC68EC000EI16
• Description: IC MPU 32BIT 16MHZ 68-PLCC
• Manufacturer: Freescale Semiconductor

Specifications of MC68EC000EI16

• Processor Type: M680x0 32-Bit
• Speed: 16MHz
• Voltage: 3.3V, 5V
• Mounting Type: Surface Mount
• Package / Case: 68-PLCC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -

DBcc
Instruction Format:
Instruction Fields:
MOTOROLA
15
0
Condition field—The binary code for one of the conditions listed in the table.
Register field—Specifies the data register used as the counter.
Displacement field—Specifies the number of bytes to branch.
14
1
13
The terminating condition is similar to the UNTIL loop clauses of
high-level languages. For example: DBMI can be stated as
"decrement and branch until minus".
Most assemblers accept DBRA for DBF for use when only a
count terminates the loop (no condition is tested).
A program can enter a loop at the beginning or by branching to
the trailing DBcc instruction. Entering the loop at the beginning
is useful for indexed addressing modes and dynamically
specified bit operations. In this case, the control index count
must be one less than the desired number of loop executions.
However, when entering a loop by branching directly to the
trailing DBcc instruction, the control count should equal the loop
execution count. In this case, if a zero count occurs, the DBcc
instruction does not branch, and the main loop is not executed.
0
12
1
M68000 FAMILY PROGRAMMER’S REFERENCE MANUAL
Test Condition, Decrement, and Branch
11
CONDITION
10
9
(M68000 Family)
16-BIT DISPLACEMENT
8
NOTE
7
1
6
1
5
0
4
0
3
1
Integer Instructions
2
REGISTER
DBcc
1
4-91
0