MC68HC908MR16CFU Freescale Semiconductor, MC68HC908MR16CFU Datasheet - Page 259

• Manufacturer Part Number: MC68HC908MR16CFU
• Description: IC MCU 8MHZ 16K FLASH 64-QFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908MR16CFU

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 44
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 10x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Enter monitor mode by either:
Once out of reset, the MCU waits for the host to send eight security bytes. After receiving the security
bytes, the MCU sends a break signal (10 consecutive logic 0s) to the host computer, indicating that it is
ready to receive a command. The break signal also provides a timing reference to allow the host to
determine the necessary baud rate.
Monitor mode uses alternate vectors for reset and SWI. The alternate vectors are in the $FE page instead
of the $FF page and allow code execution from the internal monitor firmware instead of user code. The
computer operating properly (COP) module is disabled in monitor mode as long as V
the IRQ pin or the RST pin. (See
modes of operation.)
18.3.1.3 Forced Monitor Mode
If the voltage applied to the IRQ1 is less than V
MENRST module is monitoring the reset vector fetches and will assert an internal reset if it detects that
the reset vectors are erased ($FF). When the MCU comes out of reset, it is forced into monitor mode
without requiring high voltage on the IRQ1 pin.
The COP module is disabled in forced monitor mode. Any reset other than a POR reset will automatically
force the MCU to come back to the forced monitor mode.
18.3.1.4 Data Format
Communication with the monitor ROM is in standard non-return-to-zero (NRZ) mark/space data format.
(See
The data transmit and receive rate can be anywhere from 4800 baud to 28.8 Kbaud. Transmit and receive
baud rates must be identical.
Freescale Semiconductor
•
•
Figure 18-9
Executing a software interrupt instruction (SWI) or
Applying a logic 0 and then a logic 1 to the RST pin
BREAK
$A5
START
and
BIT
START
START
BIT
BIT
Figure
BIT 0
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
BIT 0
BIT 0
18-10.)
Figure 18-10. Sample Monitor Waveforms
BIT 1
BIT 1
BIT 1
Chapter 14 System Integration Module (SIM)
Figure 18-9. Monitor Data Format
BIT 2
BIT 2
BIT 2
BIT 3
BIT 3
BIT 3
DD
BIT 4
+ V
BIT 4
BIT 4
HI
BIT 5
the MCU will come out of reset in user mode. The
BIT 5
BIT 5
BIT 6
BIT 6
BIT 6
BIT 7
BIT 7
BIT 7
STOP
BIT
STOP
STOP
BIT
BIT
START
NEXT
for more information on
BIT
START
START
NEXT
NEXT
BIT
BIT
HI
is applied to either
Monitor ROM (MON)
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