MC68332ACFC25 Freescale Semiconductor, MC68332ACFC25 Datasheet - Page 115

• Manufacturer Part Number: MC68332ACFC25
• Description: IC MCU 32BIT 25MHZ 132-PQFP
• Manufacturer: Freescale Semiconductor
• Series: M683xxr

Specifications of MC68332ACFC25

• Core Processor: CPU32
• Core Size: 32-Bit
• Speed: 25MHz
• Connectivity: EBI/EMI, SCI, SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 15
• Program Memory Type: ROMless
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 132-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -
• Data Converters: -

5.10.2.1 Enabling BDM
5.10.2.2 BDM Sources
MC68332
USER’S MANUAL
Accidentally entering BDM in a non-development environment can lock up the CPU32
when the serial command interface is not available. For this reason, BDM is enabled
during reset via the breakpoint (BKPT) signal.
BDM operation is enabled when BKPT is asserted (low), at the rising edge of RESET.
BDM remains enabled until the next system reset. A high BKPT signal on the trailing
edge of RESET disables BDM. BKPT is latched again on each rising transition of RE-
SET. BKPT is synchronized internally, and must be held low for at least two clock cy-
cles prior to negation of RESET.
BDM enable logic must be designed with special care. If hold time on BKPT extends
into the first bus cycle following reset, the bus cycle could inadvertently be tagged with
a breakpoint. Refer to the SIM Reference Manual (SIMRM/AD) for timing information.
When BDM is enabled, any of several sources can cause the transition from normal
mode to BDM. These sources include external breakpoint hardware, the BGND in-
struction, a double bus fault, and internal peripheral breakpoints. If BDM is not enabled
when an exception condition occurs, the exception is processed normally. Table 5-3
summarizes the processing of each source for both enabled and disabled cases. As
shown in Table 5-3, the BKPT instruction never causes a transition into BDM.
TARGET
SYSTEM
BGND Instruction
Double Bus Fault
BKPT Instruction
Figure 5-8 Bus State Analyzer Configuration
Source
BKPT
Freescale Semiconductor, Inc.
For More Information On This Product,
Table 5-3 BDM Source Summary
CENTRAL PROCESSING UNIT
TARGET
Go to: www.freescale.com
MCU
Opcode Substitution/
Illegal Instruction
BUS STATE
ANALYZER
BDM Enabled
Background
Background
Background
Breakpoint Exception
Opcode Substitution/
Illegal Instruction
Illegal Instruction
BDM Disabled
Halted
1129A
5-17