XE8806A SEMTECH [Semtech Corporation], XE8806A Datasheet - Page 19

• Manufacturer Part Number: XE8806A
• Description: Ultra Low-Power Low-Voltage
• Manufacturer: SEMTECH [Semtech Corporation]

Table 3-1. CPU internal register definition
bit
7
6
5
4
3
2
1
0
Table 3-2. Status register description
The CPU also has a number of flags that can be used for conditional jumps. These flags are defined in Table 3-3.
Table 3-3. Flag description
© Semtech 2006
Register name
symbol
C
V
Z
stat
i0h
i1h
i2h
i3h
iph
name
IE2
IE1
GIE
IN2
IN1
IN0
EV1
EV0
i0l
i1l
i2l
i3l
ipl
r0
r1
r2
r3
a
name
zero
carry
overflow
function
enables (when 1) the interrupt request of level 2
enables (when 1) the interrupt request of level 1
enables (when 1) all interrupt request levels
interrupt request of level 2. The interrupts labelled “low” in the interrupt handler are
routed to this interrupt level. This bit has to be cleared when the interrupt is served.
interrupt request of level 1. The interrupts labelled “mid” in the interrupt handler are
routed to this interrupt level. This bit has to be cleared when the interrupt is served.
interrupt request of level 0. The interrupts labelled “hig” in the interrupt handler are
routed to this interrupt level. This bit has to be cleared when the interrupt is served.
event request of level 1. The events labelled “low” in the event handler are routed to
this event level. This bit has to be cleared when the event is served.
event request of level 1. The events labelled “hig” in the event handler are routed to
this event level. This bit has to be cleared when the event is served.
Register function
general purpose
general purpose
general purpose
data memory offset
MSB of the data memory index i0
LBS of the data memory index i0
MSB of the data memory index i1
LBS of the data memory index i1
MSB of the data memory index i2
LBS of the data memory index i2
MSB of the data memory index i3
LBS of the data memory index i3
MSB of the program memory index ip
LBS of the program memory index ip
status register
accumulator
function
Z=1 when the accumulator a content is zero
This flag is used in shift or arithmetic operations.
For a shift operation, it has the value of the bit that was shifted out (LSB for shift
right, MSB for shift left).
For an arithmetic operation with unsigned numbers:
This flag is used in shift or arithmetic operations.
For arithmetic or shift operations with signed numbers, it is 1 if an overflow or
underflow occurs.
it is 1 at occurrence of an overflow during an addition (or equivalent).
it is 0 at occurrence of an underflow during a subtraction (or equivalent).
3-3
XE8806A/XE8807A
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