XC68HC705B32CB Freescale Semiconductor, XC68HC705B32CB Datasheet - Page 38

• Manufacturer Part Number: XC68HC705B32CB
• Description: IC MCU 2.1MHZ 32K OTP 56-DIP
• Manufacturer: Freescale Semiconductor
• Series: HC05r

Specifications of XC68HC705B32CB

• Core Processor: HC05
• Core Size: 8-Bit
• Speed: 2.1MHz
• Connectivity: SCI
• Peripherals: POR, WDT
• Number Of I /o: 32
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: OTP
• Eeprom Size: 256 x 8
• Ram Size: 528 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 8x8b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 56-SDIP (0.600", 15.24mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

2
2.5
2.5.1
Power is supplied to the microcontroller using these two pins. VDD is the positive supply and VSS
is ground.
It is in the nature of CMOS designs that very fast signal transitions occur on the MCU pins. These
short rise and fall times place very high short-duration current demands on the power supply. To
prevent noise problems, special care must be taken to provide good power supply by-passing at
the MCU. By-pass capacitors should have good high-frequency characteristics and be as close to
the MCU as possible. Bypassing requirements vary, depending on how heavily the MCU pins are
loaded.
2.5.2
This is an input-only pin for external interrupt sources. Interrupt triggering is selected using the
INTP and INTN bits in the miscellaneous register, to be one of four options detailed in
In addition, the external interrupt facility (IRQ) can be disabled using the INTE bit in the
miscellaneous register (see
the miscellaneous register while the I-bit is set. Selecting a different interrupt option will
automatically clear any pending interrupts. Further details of the external interrupt procedure can
be found in
The IRQ pin contains an internal Schmitt trigger as part of its input to improve noise immunity.
2.5.3
This active low I/O pin is used to reset the MCU. Applying a logic zero to this pin forces the device
to a known start-up state. An external RC-circuit can be connected to this pin to generate a
power-on-reset (POR) if required. In this case, the time constant must be great enough to allow
the oscillator circuit to stabilize. This input has an internal Schmitt trigger to improve noise
immunity. When a reset condition occurs internally, i.e. from the COP watchdog, the RESET pin
provides an active-low open drain output signal that may be used to reset external hardware.
2.5.4
The TCAP1 input controls the input capture 1 function of the on-chip programmable timer system.
Freescale
2-10
Section
VDD and VSS
RESET
TCAP1
IRQ
Pin descriptions
9.2.3.1.
MODES OF OPERATION AND PIN DESCRIPTIONS
Section
3.8). It is only possible to change the interrupt option bits in
MC68HC05B6
Table
Rev. 4.1
9-3.