MC68HC908LB8CPE Freescale Semiconductor, MC68HC908LB8CPE Datasheet - Page 214

• Manufacturer Part Number: MC68HC908LB8CPE
• Description: IC MCU 8K FLASH 8MHZ 20DIP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908LB8CPE

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Peripherals: LVR, POR, PWM
• Number Of I /o: 18
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 7x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Connectivity: -

Development Support
If entering monitor mode without high voltage on IRQ (above condition set 2 or 3, where applied voltage
is V
to reduce circuit requirements when performing in-circuit programming.
19.3.1.1 Normal Monitor Mode
RST and OSC1 functions will be active on the PTA5 and PTC0 pins, respectively, as long as V
applied to the IRQ pin. If the IRQ pin is lowered (no longer V
monitor mode, but the pin functions will be determined by the settings in the configuration register when
V
When monitor mode is entered with V
long as V
after entering monitor mode, then the COP will be disabled.
19.3.1.2 Forced Monitor Mode
If the voltage applied to the IRQ1 is less than V
However, when the reset vector is erased ($FFFF), the MCU is forced into monitor mode without requiring
high voltage on the IRQ1 pin. Once out of reset, the monitor code is initially executing off the internal clock
at its default frequency.
If IRQ is tied high (V
which will operate as a serial communication port and OSC1 input respectively (refer to
That will allow the clock to be driven from an external source through OSC1 pin.
If IRQ is tied low, all pins will default to regular input port function except for PTA0 which will operate as
serial communication port. Refer to
as a port input pin in monitor mode.
The COP module is disabled in forced monitor mode.
19.3.1.3 Monitor Vectors
In monitor mode, the MCU uses different vectors for reset, SWI (software interrupt), and break interrupt
than those for user mode. 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.
Table 19-2
214
TST
DD
was lowered. See
or V
TST
SS
summarizes the differences between user mode and monitor mode regarding vectors.
User
Monitor
), then startup port pin requirements and conditions, (PTA1/PTA4) are not in effect. This is
is applied to IRQ. This condition states that as long as V
Modes
If the reset vector is blank and monitor mode is entered, the chip will see an
additional reset cycle after the initial power-on reset (POR). Once the part
has been programmed, the traditional method of applying a voltage, V
to IRQ must be used to enter monitor mode.
DD
), all pins will default to regular input port functions except for PTA0 and PTC0
Chapter 5 Configuration Register
Vector
$FFFE
$FEFE
Reset
High
Figure
MC68HC908LB8 Data Sheet, Rev. 1
Table 19-2. Mode Difference
TST
Vector
$FEFF
$FFFF
Reset
Low
on IRQ, the computer operating properly (COP) is disabled as
19-12. Regardless of the state of the IRQ pin, it will not function
TST
NOTE
Vector
$FFFC
$FEFC
Break
High
, the MCU will come out of reset in user mode.
Functions
(CONFIG).
TST
Vector
$FFFD
$FEFD
Break
Low
) then the chip will still be operating in
TST
Vector
$FFFC
$FEFC
High
SWI
is maintained on the IRQ pin
Freescale Semiconductor
Vector
$FFFD
$FEFD
TST
Low
SWI
Figure
,
TST
19-11).
is