MC68HC711P2CFN4 Freescale Semiconductor, MC68HC711P2CFN4 Datasheet - Page 28

• Manufacturer Part Number: MC68HC711P2CFN4
• Description: IC MCU 32K OTP 4MHZ 84-PLCC
• Manufacturer: Freescale Semiconductor
• Series: HC11r

Specifications of MC68HC711P2CFN4

• Core Processor: HC11
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: MI Bus, SCI, SPI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 50
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: OTP
• Eeprom Size: 640 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 8x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 84-PLCC
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Pin Descriptions
2.7.2 Changing the PLL frequency
2.7.3 PLL registers
2.7.3.1 PLLCR — PLL control register
Technical Data
PLL control (PLLCR)
To change the PLL frequency it is necessary to perform the following
sequence of events, in order to prevent possible bursts of high frequency
operation during the reconfiguration of the PLL:
Two registers are used to control the operation of the MC68HC11P2
phase-locked loop circuitry. These are the PLL control register and the
synthesizer program register, each of which is described below.
This read/write register contains two bits that are used to enable and
disable the synthesizer and to switch from slow (EXTAL) to one of the
fast speeds. Two further bits are used to control the filter bandwidth. The
SCI and timer clock source and the slow clock for WAIT mode are also
controlled by this register.
PLLON — PLL on
1. Switch to the low frequency bus rate (BCS = 0)
2. Disable the PLL (PLLON = 0)
3. Change the value in SYNR
4. Enable the PLL (PLLON = 1)
5. Wait a time t
6. Switch to the high frequency bus rate (BCS = 1)
Freescale Semiconductor, Inc.
Address bit 7
For More Information On This Product,
$002E PLLON BCS AUTO BWC VCOT MCS
1 = Switch PLL on.
0 = Switch PLL off.
Go to: www.freescale.com
Pin Descriptions
PLLS
bit 6
for the PLL frequency to stabilize
bit 5
bit 4
bit 3
bit 2
MC68HC11P2 — Rev 1.0
bit 1
LCK
WEN 1010 1000
bit 0
on reset
State