20-668-0024 Rabbit Semiconductor, 20-668-0024 Datasheet - Page 300

• Manufacturer Part Number: 20-668-0024
• Description: IC CPU RABBIT4000 128-LQFP
• Manufacturer: Rabbit Semiconductor

Specifications of 20-668-0024

• Processor Type: Rabbit 4000 8-bit
• Speed: 60MHz
• Voltage: 2.5V, 2.7V, 3V, 3.3V
• Mounting Type: Surface Mount
• Package / Case: 128-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Other names: 20-668-0022; 316-1078

27.3.5 System/User Mode Instructions
Seven instructions exist primarily to support the System/User Mode, and are listed in
Table 27-3. Note that
always perform that operation (but will have special behavior when the System/User
Mode is enabled and the processor is in System Mode). In addition, if the ALTD prefix
appears before the instruction,
not occur.
The processor keeps a one-byte stack (called the SU register) that is analogous to the IP
register that keeps track of the interrupt priority. Every time
the User Mode), or an interrupt occurs, or
Mode), the current mode is pushed onto the SU register. When a
previous mode is popped off the SU register.
290
SETUSR
PUSH SU
POP SU
SURES
IDET
RDMODE
SYSCALL
SCALL
SRET
SETUSRP mn
SETSYSP mn
Instruction
Bytes
2
2
2
2
1
2
2
2
2
4
4
Table 27-3. System/User Mode Instructions
IDET
clk
10
15
12
15
12
4
9
7
4
2
4
shares the value of
A I S Z V C
LD E’,E
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
is always executed and the special behavior does
-
-
-
-
-
- * CF = SU[0]
-
-
-
-
-
SYSCALL
- SU = {SU[5:0], 0x01}
- (SP-1) = SU; SP = SP - 1
- SU = (SP); SP = SP + 1
- SU = {SU[1:0], SU[7:2]}
-
-
-
-
-
-
Performs
(EDMF && SU[0]) then the System
Violation interrupt flag is set; if ALTD
appears before it always does
SP = SP - 2; PC = {R,v} where
v = SYSCALL offset
(SP-1) = PCH; (SP-2) = PCL; (SP-3) = SU;
SP = SP - 3; PC = {IIR, 01100000};
SU = {SU[5:0], 00}
SP = SP+3
SU = {SU[7:2], 01}, (SP-1) = m;
(SP-2) = n; SP = SP-2
SU = {SU[1:0], SU[7:2]}; tmpl = (SP);
tmph = (SP+1); SP = SP+2;
if {tmp ! = mn} System Violation
LD E,E
SU = (SP); PCL = (SP+1); PCH = (SP+2);
Rabbit 4000 Microprocessor User’s Manual
or
LD E,E
RST
in the opcode table, and will
SETUSR
Operation
is executed (to enter System
, but if
SURES
is executed (to enter
LD E’,E
is executed, the
Priv
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No