AT89LP51ED2-20MU Atmel, AT89LP51ED2-20MU Datasheet - Page 104

• Manufacturer Part Number: AT89LP51ED2-20MU
• Description: 8-bit Microcontrollers - MCU 64KB 20MHz 2.4V-5.5V
• Manufacturer: Atmel

Specifications of AT89LP51ED2-20MU

• Rohs: yes
• Core: 8051
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 20 MHz
• Program Memory Size: 64 KB
• Data Ram Size: 256 B
• On-chip Adc: Yes
• Operating Supply Voltage: 2.4 V to 5.5 V
• Operating Temperature Range: - 40 C to + 85 C
• Package / Case: VQFN-44
• Mounting Style: SMD/SMT
• Data Rom Size: 4 KB
• Interface Type: 2-Wire, SPI, UART
• Number Of Programmable I/os: 36
• Number Of Timers: 3
• Processor Series: AT89x
• Program Memory Type: Flash
• Factory Pack Quantity: 360

15.5
104
High Speed Output Mode
AT89LP51RD2/ED2/ID2 Preliminary
In this mode the CEX output (on port 1) associated with the PCA module will toggle each time a
match occurs between the PCA counter and the modules capture registers as shown in
15-6. To activate this mode the TOG, MAT, and ECOM bits in the module's CCAPMn SFR must
be set (See
A prior write must be done to CCAPnL and CCAPnH before writing the ECOMn bit.
Figure 15-5. PCA High Speed Output Mode
Before enabling ECOM bit, CCAPnL and CCAPnH should be set with a non zero value, other-
wise an unwanted match could happen. Once ECOM is set, writing CCAPnL will clear ECOM so
that an unwanted match doesn’t occur while modifying the compare value. Writing to CCAPnH
will set ECOM. For this reason, user software should write CCAPnL first, and then CCAPnH. Of
course, the ECOM bit can still be controlled by accessing to CCAPMn register.
An example of a High Speed Output waveform is shown in
output can be controlled by reloading the PCA Timer in software and/or changing the compare
values multiple times per timeout period.
Figure 15-6. High Speed Output Waveform
{CCAPnH,CCAPnL}
{CH,CL} = FFFFH
{CH,CL} = 0000H
CCAPnL CCAPnH
Figure
CL
CEXn
CCAPnH
Write to
15-5).
CH
1
ECOMn
=
0
CCAPMn.3
CCAPMn.2
TOGn
MATn
Write to
CCAPnL
TOGn = 1, ECOMn = 1
CCFn
CCAPMn.0
ECCFn
Figure
Module n
15-6. The frequency of the
Interrupt
CEXn
3714A–MICRO–7/11
Figure