668-0010 Rabbit Semiconductor, 668-0010 Datasheet - Page 230

• Manufacturer Part Number: 668-0010
• Description: IC MPU RABIT3000 55.5MHZ 128LQFP
• Manufacturer: Rabbit Semiconductor

Specifications of 668-0010

• Rohs Status: RoHS non-compliant
• Processor Type: Rabbit 3000 8-Bit
• Speed: 55.5MHz
• Voltage: 2.5V, 2.7V, 3V, 3.3V
• Mounting Type: Surface Mount
• Package / Case: 128-LQFP
• Features: -
• Other names: 316-1016

26.3.5 System/User Mode Instructions
Seven new opcodes have been added to support the System/User mode, and are listed in
Table 26-3. All but
shares the value of
System/User mode is disabled, or when it is enabled and in the System mode. In addition,
if the
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
tem mode), the current mode is pushed onto the SU register. When a
the previous mode is popped off the SU register.
The effects of each opcode are:
• The
•
•
•
•
•
220
SETUSR
PUSH SU
POP SU
SURES
IDET
RDMODE
SYSCALL
Instruction
into the SU register.
PUSH SU
SURES
mode.
IDET
mode.
RDMODE
SYSCALL
the System mode without using one of the existing
into the System mode and execute code in the corresponding interrupt-vector table entry.
ALTD
SETUSR
causes an interrupt if executed in the User mode, and does nothing in the System
pops the current processor mode off the SU register, returning it to the previous
returns the current mode in the carry flag (0 for System mode, 1 for User mode).
prefix appears before the opcode,
is essentially a new
and
Bytes
opcode puts the processor into the User mode by pushing the correct value
POP SU
2
2
2
2
1
2
2
LD E,E
IDET
Table 26-3. New System/User Mode Opcodes
clk
10
4
9
7
4
2
4
are placed in previously empty opcode table assignments.
push and pop the single-byte SU register on/off the SP stack.
in the opcode table, and will perform that operation when the
A I S Z V C
RST
-
-
-
-
-
-
-
-
-
-
-
-
-
-
opcode, and was added to allow User mode access to
-
-
-
-
-
-
-
-
-
-
-
-
- * 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]}
-
-
LD E’,E
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
Rabbit 3000 Microprocessor User’s Manual
or
RST
RST
LD E,E
is always executed instead.
opcodes. It will put the processor
is executed (to enter the Sys-
SETUSR
Operation
, but if
SURES
is executed (to enter
LD E’,E
is executed,
IDET
Priv
Yes
Yes
Yes
Yes
Yes
No
No
?