MC68HC908GR4CFA Freescale Semiconductor, MC68HC908GR4CFA Datasheet - Page 192

• Manufacturer Part Number: MC68HC908GR4CFA
• Description: IC MCU 4K FLASH 8.2MHZ 32-LQFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908GR4CFA

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 21
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: FLASH
• Ram Size: 384 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 6x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Monitor ROM (MON)
15.4.1 Entering Monitor Mode
Technical Data
192
The monitor code has been updated from previous versions to allow
enabling the PLL to generate the internal clock, provided the reset vector
is blank, when the device is being clocked by a low-frequency crystal.
This addition, which is enabled when IRQ is held low out of rest, is
intended to support serial communication/ programming at 9600 baud in
monitor mode by stepping up the external frequency (assumed to be
32.768 kHz) by a fixed amount to generate the desired internal
frequency (2.4576 MHz). Since this feature is enabled only when IRQ is
held low out of reset, it cannot be used when the reset vector is not blank
because entry into monitor mode in this case requires V
Table 15-1
specified in the table, monitor mode may be entered after a power-on
reset (POR) and will allow communication at 9600 baud provided one of
the following sets of conditions is met:
1. If $FFFE and $FFFF contain values not cared:
2. If $FFFE and $FFFF contain $FF, blank state:
3. If $FFFE and $FFFF contain $FF, blank state:
Freescale Semiconductor, Inc.
For More Information On This Product,
– The external clock is 9.8304 MHz
– IRQ = V
– The external clock is 9.8304 MHz
– IRQ = V
– The external clock is 32.768 kHz (crystal)
– IRQ = V
pullup; PLL off)
32.768 kHz to an internal bus frequency of 2.4576 MHz)
shows the pin conditions for entering monitor mode. As
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Monitor ROM (MON)
DD
TST
SS
(this setting initiates the PLL to boost the external
(this can be implemented through the internal IRQ
(PLL off)
MC68HC908GR8 — Rev 4.0
TST
on IRQ.
MOTOROLA