mc68hc916y3 Freescale Semiconductor, Inc, mc68hc916y3 Datasheet - Page 66

• Manufacturer Part Number: mc68hc916y3
• Description: Mc68hc16y3 16 Bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

4.2.5 Condition Code Register
S — STOP Enable
MV — Accumulator M overflow flag
H — Half Carry Flag
EV — Accumulator M Extension Overflow Flag
N — Negative Flag
Z — Zero Flag
V — Overflow Flag
C — Carry Flag
IP[2:0] — Interrupt Priority Field
4-4
MOTOROLA
15
S
The 16-bit condition code register is composed of two functional blocks. The eight
MSB, which correspond to the CCR on the M68HC11, contain the low-power stop con-
trol bit and processor status flags. The eight LSB contain the interrupt priority field, the
DSP saturation mode control bit, and the program counter address extension field.
Figure 4-2 shows the condition code register. Detailed descriptions of each status in-
dicator and field in the register follow the figure.
MV is set when an overflow into AM35 has occurred.
H is set when a carry from A3 or B3 occurs during BCD addition.
EV is set when an overflow into AM31 has occurred.
N is set under the following conditions:
Z is set under the following conditions:
V is set when a two’s complement overflow occurs as the result of an operation.
C is set when a carry or borrow occurs during an arithmetic operation. This flag is also
used during shift and rotate to facilitate multiple word operations.
The priority value in this field (0 to 7) is used to mask interrupts.
0 = Stop clock when LPSTOP instruction is executed
1 = Perform NOP when LPSTOP instruction is executed
• When the MSB is set in the operand of a read operation.
• When the MSB is set in the result of a logic or arithmetic operation.
• When all bits are zero in the operand of a read operation.
• When all bits are zero in the result of a logic or arithmetic operation.
MV
14
13
H
EV
12
Freescale Semiconductor, Inc.
11
N
Figure 4-2 Condition Code Register
For More Information On This Product,
10
Z
Go to: www.freescale.com
9
V
C
8
7
IP[2:0]
6
5
SM
4
3
MC68HC16Y3/916Y3
USER’S MANUAL
2
PK[3:0]
1
0