MC68EC000EI20 Freescale Semiconductor, MC68EC000EI20 Datasheet - Page 21

• Manufacturer Part Number: MC68EC000EI20
• Description: IC MPU 32BIT 20MHZ 68-PLCC
• Manufacturer: Freescale Semiconductor

Specifications of MC68EC000EI20

• Processor Type: M680x0 32-Bit
• Speed: 20MHz
• Voltage: 3.3V, 5V
• Mounting Type: Surface Mount
• Package / Case: 68-PLCC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -

Introduction
1.3.1 Address Register 7 (A7)
In the supervisor programming model register, A7 refers to the interrupt stack pointer,
A7’(ISP) and the master stack pointer, A7" (MSP). The supervisor stack pointer is the active
stack pointer (ISP or MSP). For processors that do not support ISP or MSP, the system stack
is the system stack pointer (SSP). The ISP and MSP are general- purpose address registers
for the supervisor mode. They can be used as software stack pointers, index registers, or
base address registers. The ISP and MSP can be used for word and long-word operations.
1.3.2 Status Register
Figure 1-8 illustrates the SR, which stores the processor status and contains the condition
codes that reflect the results of a previous operation. In the supervisor mode, software can
access the full SR, including the interrupt priority mask and additional control bits. These bits
indicate the following states for the processor: one of two trace modes (T1, T0), supervisor
or user mode (S), and master or interrupt mode (M). For the MC68000, MC68EC000,
MC68008, MC68010, MC68HC000, MC68HC001, and CPU32, only one trace mode
1-10
AC
CAL
CRP
DRP
PCSR
PMMUSR,
MMUSR
SCC
SRP
TC
URP
VAL
PMMUSR =
MMUSR
M68000 FAMILY PROGRAMMER’S REFERENCE MANUAL
PCSR
Registers
CRP
DRP
SCC
URP
SRP
CAL
VAL
AC
TC
Related To Paged Memory Management
Table 1-2. Supervisor Registers
=
=
=
=
=
=
=
=
=
=
=
Access Control Register
Current Access Level Register
CPU Root Pointer
DMA Root Pointer
PMMU Control Register
Paged Memory Management Unit Status Register
Memory Management Unit Status Register
Stack Change Control Register
Supervisor Root Pointer Register
Translation Control Register
User Root Pointer
Valid Access Level Register
68851
x
x
x
x
x
x
x
x
x
x
68030
x
x
x
x
Devices
68040
x
x
x
x
68LC040
x
x
x
x
MOTOROLA