MC68EC000EI12 Freescale Semiconductor, MC68EC000EI12 Datasheet - Page 390

• Manufacturer Part Number: MC68EC000EI12
• Description: IC MPU 32BIT 12MHZ 68-PLCC
• Manufacturer: Freescale Semiconductor
• Series: 68K - M680X0r

Specifications of MC68EC000EI12

• Processor Type: M680x0 32-Bit
• Speed: 12MHz
• Voltage: 3.3V, 5V
• Mounting Type: Surface Mount
• Package / Case: 68-PLCC
• Core Size: 32 Bit
• Cpu Speed: 12MHz
• 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: 12MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -

Floating Point Instructions
FMOVEM
Register List field:
Programming Note: This instruction provides a very useful feature, dynamic register list
5-88
dr field—Specifies the direction of the transfer.
specification, that can significantly enhance system performance. If the calling
conventions used for procedure calls utilize the dynamic register list feature, the
number of floating-point data registers saved and restored can be reduced.
Static list—contains the register select mask. If a register is to be moved, the corre-
sponding bit in the mask is set as shown below; otherwise it is clear.
Dynamic list—contains the integer data register number, rrr, as listed in the following
table:
The format of the dynamic list mask is the same as for the static list and is contained
in the least significant eight bits of the specified main processor data register.
To utilize the dynamic register specification feature of the FMOVEM instruction, both
the calling and the called procedures must be written to communicate information
about register usage. When one procedure calls another, a register mask must be
passed to the called procedure to indicate which registers must not be altered upon
return to the calling procedure. The called procedure then saves only those registers
that are modified and are already in use. Several techniques can be used to utilize this
mechanism, and an example follows.
Mode field—Specifies the type of the register list and addressing mode.
00 — Static register list, predecrement addressing mode.
01 — Dynamic register list, predecrement addressing mode.
10 — Static register list, postincrement or control addressing mode.
11 — Dynamic register list, postincrement or control addressing mode.
0 — Move the listed registers from memory to the floating-point unit.
1 — Move the listed registers from the floating-point unit to memory.
Static, (An) + ,
Static, – (An)
or Control
List Type
Dynamic
M68000 FAMILY PROGRAMMER’S REFERENCE MANUAL
Move Multiple Floating-Point
FP7
FP0
0
(MC6888X, MC68040)
Data Registers
FP6
FP1
r
FP5
FP2
r
Register List Format
FP4
FP3
r
FP3
FP4
0
FP2
FP5
0
FP1
FP6
0
FMOVEM
FP0
FP7
0
MOTOROLA