MC68302EH16C Freescale Semiconductor, MC68302EH16C Datasheet - Page 38

• Manufacturer Part Number: MC68302EH16C
• Description: IC MPU MULTI-PROTOCOL 132-PQFP
• Manufacturer: Freescale Semiconductor

Specifications of MC68302EH16C

• Processor Type: M683xx 32-Bit
• Speed: 16MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 132-MQFP, 132-PQFP
• Controller Family/series: 68K
• Core Size: 32 Bit
• Ram Memory Size: 1152Byte
• Cpu Speed: 16MHz
• No. Of Timers: 3
• Embedded Interface Type: SCP, TDM
• Digital Ic Case Style: PQFP
• Rohs Compliant: Yes
• Family Name: M68000
• Device Core: ColdFire
• Device Core Size: 32b
• Frequency (max): 16MHz
• Instruction Set Architecture: RISC
• Supply Voltage 1 (typ): 5V
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 132
• Package Type: PQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

MC68000/MC68008 Core
Once the processor is in the user state and executing instructions, only exception process-
ing can change the privilege state. During exception processing, the current state of the S
bit in the SR is saved and the S bit is asserted, putting the processor in the supervisor state.
Therefore, when instruction execution resumes at the address specified to process the ex-
ception, the processor is in the supervisor privilege state. The transition from the supervisor
to user state can be accomplished by any of four instructions: return from exception (RTE),
move to status register (MOVE to SR), AND immediate to status register (ANDI to SR), and
exclusive OR immediate to status register (EORI to SR).
2.4 EXCEPTION PROCESSING
The processing of an exception occurs in four steps, with variations for different exception
causes. During the first step, a temporary copy of the SR is made, and the SR is set for ex-
ception processing. During the second step, the exception vector is determined; during the
third step, the current processor context is saved. During the fourth step, a new context is
obtained, and the processor switches to instruction processing.
2.4.1 Exception Vectors
Exception vectors are memory locations from which the processor fetches the address of a
routine to handle that exception. All exception vectors are two words long except for the re-
set vector, which is four words. All exception vectors lie in the supervisor data space except
for the reset vector, which is in the supervisor program space. A vector number is an 8-bit
number which, when multiplied by four, gives the offset of the exception vector. Vector num-
bers are generated internally or externally, depending on the cause of the exception. In the
case of interrupts, during the interrupt acknowledge bus cycle, a peripheral may provide an
8-bit vector number to the processor on data bus lines D7–D0. Alternatively, the peripheral
may assert autovector (AVEC) instead of data transfer acknowledge (DTACK) to request an
autovector for that priority level of interrupt. The exception vector assignments for the
M68000 processor are shown in Table 2-5.
2-8
Number
Vector
10
0
1
3
4
5
6
7
8
9
2
Table 2-5. M68000 Exception Vector Assignment
Decimal
12
16
20
24
28
32
36
40
0
4
8
Address
MC68302 USER’S MANUAL
Hex
00C
01C
000
004
008
010
014
018
020
024
028
Space
SP
SP
SD
SD
SD
SD
SD
SD
SD
SD
SD
Reset: Initial SSP
Reset: Initial PC
Bus Error
Address Error
Illegal Instruction
Zero Divide
CHK Instruction
TRAPV Instruction
Privilege Violation
Trace
Line 1010 Emulator
Assignment
2
2
MOTOROLA