MC68HC16Z1CPV25 Freescale Semiconductor, MC68HC16Z1CPV25 Datasheet - Page 134

• Manufacturer Part Number: MC68HC16Z1CPV25
• Description: IC MPU 1K RAM 25MHZ 144-LQFP
• Manufacturer: Freescale Semiconductor
• Series: HC16r

Specifications of MC68HC16Z1CPV25

• Core Processor: CPU16
• Core Size: 16-Bit
• Speed: 25MHz
• Connectivity: EBI/EMI, SCI, SPI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 16
• Program Memory Type: ROMless
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 144-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -
• Other names: Q1141110

5.4.7 Interrupt Priority and Vectoring
5-28
The periodic interrupt timer modulus counter is clocked by one of two signals. When
the PLL is enabled (MODCLK = 1 during reset), f
cillator; f
CLK = 0 during reset), f
in the periodic interrupt timer register (PITR) determines system clock prescaling for
the periodic interrupt timer. One of two options, either no prescaling, or prescaling by
a factor of 512, can be selected. The value of PTP is affected by the state of the MOD-
CLK pin during reset, as shown in
ue.
Either clock signal selected by the PTP is divided by four before driving the modulus
counter. The modulus counter is initialized by writing a value to the periodic interrupt
timer modulus (PITM[7:0]) field in PITR. A zero value turns off the periodic timer. When
the modulus counter value reaches zero, an interrupt is generated. The modulus
counter is then reloaded with the value in PITM[7:0] and counting repeats. If a new val-
ue is written to PITR, it is loaded into the modulus counter when the current count is
completed.
The following equation calculates the PIT period when a slow reference frequency is
used:
The following equation calculates the PIT period when a fast reference frequency is
used:
The following equation calculates the PIT period for an externally input clock frequen-
cy on both slow and fast reference frequency devices.
Interrupt priority and vectoring are determined by the values of the periodic interrupt
request level (PIRQL[2:0]) and periodic interrupt vector (PIV) fields in the periodic in-
terrupt control register (PICR).
ref
128 is used with fast reference oscillator. When the PLL is disabled (MOD-
PIT Period
PIT Period
PIT Period
Table 5-11 MODCLK Pin and PTP Bit at Reset
Freescale Semiconductor, Inc.
For More Information On This Product,
ref
0 (External Clock)
=
1 (Internal Clock)
SYSTEM INTEGRATION MODULE
------------------------------------------------------------------------------------------------------------------------------- -----
is used. The value of the periodic timer prescaler (PTP) bit
=
=
MODCLK
128 PITM[7:0] 1 if PTP = 0, 512 if PTP = 1 4
-------------------------------------------------------------------------------------------------------------------- -
-------------------------------------------------------------------------------------------------------------------- -
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PITM[7:0] 1 if PTP = 0, 512 if PTP = 1 4
PITM[7:0] 1 if PTP = 0, 512 if PTP = 1 4
Table
5-11. System software can change PTP val-
1 ( 512)
0 ( 1)
PTP
ref
f
f
f
sys
ref
ref
is used with a slow reference os-
M68HC16 Z SERIES
USER’S MANUAL