SAF-XC878CM-16FFI Infineon Technologies, SAF-XC878CM-16FFI Datasheet - Page 84

• Manufacturer Part Number: SAF-XC878CM-16FFI
• Description: MCU, 8BIT, 64K FLASH, 5V, 64LQFP
• Manufacturer: Infineon Technologies

Specifications of SAF-XC878CM-16FFI

• Controller Family/series: XC800
• Core Size: 8bit
• Program Memory Size: 64KB
• Ram Memory Size: 3328Byte
• No. Of Timers: 4
• No. Of Pwm Channels: 10
• Digital Ic Case Style: LQFP
• Supply Voltage Range: 4.5V To
• Peripherals: ADC, PWM, Timer
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

not be bypassed for this PLL mode. The PLL mode is used during normal system
operation.
System Frequency Selection
For the XC878, the value of NF, NR and OD can be selected by bits NDIV, PDIV and
KDIV respectively for different oscillator inputs inorder to obtain the required fsys. But the
combination of these factors must fulfill the following condition:
•
•
Table 26
and maximum frequency of 160 MHz (CPU clock = 26.67 MHz)can be obtained for the
different oscillator sources.
Table 26
Oscillator
On-chip
External
3.8.1
The oscillator circuit, a Pierce oscillator, is designed to work with both, an external crystal
oscillator or an external stable clock source. It basically consists of an inverting amplifier
and a feedback element with XTAL1 as input, and XTAL2 as output.
When using a crystal, a proper external oscillator circuitry must be connected to both
pins, XTAL1 and XTAL2. The crystal frequency can be within the range of 2 MHz to
20 MHz. Additionally, it is necessary to have two load capacitances
depending on the crystal type, a series resistor
may be temporarily inserted to measure the oscillation allowance (negative resistance)
of the oscillator circuitry.
external feedback resistor
values and related operating range are dependent on the crystal frequency and have to
be determined and optimized together with the crystal vendor using the negative
Data Sheet
100 MHz < f
800 KHz < f
provides examples on how the typical system frequency of fsys = 144 MHz
Recommended External Oscillator Circuits
System frequency (
OSC
VCO
/ (2 * NR) < 8 MHz
< 175 MHz
fosc
4 MHz
8 MHz
6 MHz
4 MHz
4 MHz
R
R
f
Q
is also required in the external oscillator circuitry. The exact
values are typically specified by the crystal vendor. An
f
SYS
f
N
72
80
72
72
72
sys
=
= 144 MHz)
f
OSC
75
x
P
2
2
4
3
2
NR
R
X2
NF
x
, to limit the current. A test resistor
OD
K
1
1
1
1
1
fsys
144 MHz
160 MHz
144 MHz
144 MHz
144 MHz
Functional Description
C
X1
and
XC878CLM
V1.2, 2009-11
C
X2
, and
(3.2)
R
Q