AT89LP6440-20AU Atmel, AT89LP6440-20AU Datasheet - Page 38

• Manufacturer Part Number: AT89LP6440-20AU
• Description: MCU 8051 64K FLASH ISP 44TQFP
• Manufacturer: Atmel
• Series: 89LPr

Specifications of AT89LP6440-20AU

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 38
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 8K x 8
• Ram Size: 4.25K x 8
• Voltage - Supply (vcc/vdd): 2.4 V ~ 3.6 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Package: 44TQFP
• Device Core: 8051
• Family Name: 89LP
• Maximum Speed: 20 MHz
• Operating Supply Voltage: 2.5|3.3 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 38
• Interface Type: 2-Wire/SPI
• On-chip Dac: 8-chx10-bit
• Number Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.3.2
8.3.3
9. Interrupts
38
AT89LP6440 - Preliminary
Analog Comparators
Analog-to-Digital Converter
Figure 8-3.
The comparators will operate during Idle mode if enabled. To save power, the comparators
should be disabled before entering Idle mode if possible. When the comparators are turned off
and on again, some settling time is required for the analog circuits to stabilize. If the comparators
are enabled, they will consume the least power when using an external reference, RFA
and RFB
The DADC will operate during Idle mode if enabled. To save power, the DADC should be dis-
abled before entering Idle mode if possible. When the DADC is turned off and on again, some
settling time is required for the analog circuits to stabilize. If the DADC is enabled, it will con-
sume the least power when configured to use the system clock instead of the internal RC
oscillator (unless the IRC is the system clock source) and when the internal reference is disabled
(IREF = 0). The DADC must always be disabled before entering power-down.
The AT89LP6440 provides 12 interrupt sources: two external interrupts, three timer interrupts, a
serial port interrupt, an analog comparator interrupt, a general-purpose interrupt, a com-
pare/capture interrupt, a two-wire interrupt, an ADC interrupt and an SPI interrupt. These
interrupts and the system reset each have a separate program vector at the start of the program
memory space. Each interrupt source can be individually enabled or disabled by setting or clear-
ing a bit in the interrupt enable registers IE and IE2. The IE register also contains a global
disable bit, EA, which disables all interrupts.
Each interrupt source can be individually programmed to one of four priority levels by setting or
clearing bits in the interrupt priority registers IP, IPH, IP2 and IP2H. IP and IP2 hold the low order
priority bits and IPH and IP2H hold the high priority bits for each interrupt. An interrupt service
routine in progress can be interrupted by a higher priority interrupt, but not by another interrupt of
the same or lower priority. The highest priority interrupt cannot be interrupted by any other inter-
rupt source. If two requests of different priority levels are pending at the end of an instruction, the
request of higher priority level is serviced. If requests of the same priority level are pending at
the end of an instruction, an internal polling sequence determines which request is serviced. The
polling sequence is based on the vector address; an interrupt with a lower vector address has
higher priority than an interrupt with a higher vector address. Note that the polling sequence is
only used to resolve pending requests of the same priority level.
Internal
Internal
XTAL1
Reset
Clock
PWD
RST
1-0
= 00B.
Reset Recovery from Power-down
t SUT
3706A–MICRO–9/09
1-0
= 00B