MC68EC000EI8 Freescale Semiconductor, MC68EC000EI8 Datasheet - Page 465

• Manufacturer Part Number: MC68EC000EI8
• Description: IC MPU 32BIT 85MHZ 68-PLCC
• Manufacturer: Freescale Semiconductor
• Series: M68000r

Specifications of MC68EC000EI8

• Processor Type: M680x0 32-Bit
• Speed: 8MHz
• Voltage: 3.3V, 5V
• Mounting Type: Surface Mount
• Package / Case: 68-PLCC
• Core Size: 32 Bit
• Cpu Speed: 8MHz
• Digital Ic Case Style: PLCC
• No. Of Pins: 68
• Supply Voltage Range: 3V To 3.6V
• Operating Temperature Range: 0°C To +70°C
• Filter Terminals: SMD
• Rohs Compliant: Yes
• Clock Frequency: 8MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -

FRESTORE
Operation:
Assembler
Syntax:
Attributes:
Description: Aborts the execution of any floating-point operation in progress and loads a
MOTOROLA
new floating-point unit internal state from the state frame located at the effective
address. The first word at the specified address is the format word of the state frame.
It specifies the size of the frame and the revision number of the floating-point unit that
created it. A format word is invalid if it does not recognize the size of the frame or the
revision number does not match the revision of the floating-point unit. If the format word
is invalid, FRESTORE aborts, and a format exception is generated. If the format word
is valid, the appropriate state frame is loaded, starting at the specified location and
proceeding through higher addresses.
The FRESTORE instruction does not normally affect the programmer’s model registers
of the floating-point coprocessor, except for the NULL state size, as described below.
It is only for restoring the user invisible portion of the machine. The FRESTORE
instruction is used with the FMOVEM instruction to perform a full context restoration of
the floating-point unit, including the floating- point data registers and system control
registers. To accomplish a complete restoration, the FMOVEM instructions are first
executed to load the programmer’s model, followed by the FRESTORE instruction to
load the internal state and continue any previously suspended operation.
M68000 FAMILY PROGRAMMER’S REFERENCE MANUAL
If in Supervisor State
ELSE TRAP
FRESTORE < ea >
Unsized
Then FPU State Frame
(MC68881, MC68882, MC68040 only)
Floating-Point State
Restore Internal
Internal State
Supervisor (Privileged) Instructions
FRESTORE
6-11