AT89LP428-20AU Atmel, AT89LP428-20AU Datasheet - Page 122

• Manufacturer Part Number: AT89LP428-20AU
• Description: MCU 8051 4K FLASH SPI 32TQFP
• Manufacturer: Atmel
• Series: 89LPr

Specifications of AT89LP428-20AU

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 30
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 2.4 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-TQFP, 32-VQFP
• Processor Series: AT89x
• Core: 8051
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: AT89ISP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -
• Lead Free Status / Rohs Status: Details

23.8
23.9
23.9.1
122
User Signature and Analog Configuration
Programming Interface Timing
AT89LP428/828
Power-up Sequence
The User Signature Array contains 128 bytes of nonvolatile memory in two 64-byte pages. The
first page of the User Signature Array (0000H - 003FH) is available for serial numbers, firmware
revision information, date codes or other user parameters. The User Signature Array may only
be written by an external device when the User Signature Programming Fuse is enabled. When
the fuse is enabled, Chip Erase will also erase the first page of the array. When the fuse is dis-
abled, the array is not affected by write or erase commands. Programming of the Signature
Array can also be disabled by the Lock Bits. However, reading the signature is always allowed
and the array should not be used to store security sensitive information. The User Signature
Array may be modified during execution through the In-Application Programming interface,
regardless of the state of the User Signature Programming fuse or Lock Bits, provided that the
IAP Fuse is enabled. Note that the address of the User Signature Array, as seen by
the IAP interface, equals the User Signature address plus 128 (0080H - 00FFH instead of
0000H - 007FH).
The second page of the User Signature Array (0040H - 007FH) contains analog configuration
parameters for the AT89LP428/828. Each byte represents a parameter as listed in
7
accordingly. The second page of the array is not affected by Chip Erase. Other bytes in this
page may be used as additional signature space; however, care should be taken to preserve the
parameter values when modifying other bytes.
Table 23-7.
This section details general system timing sequences and constraints for entering or exiting In-
System Programming as well as parameters related to the Serial Peripheral Interface during
ISP. The general timing parameters for the following waveform figures are listed in section
ing Parameters” on page
Execute this sequence to enter programming mode immediately after power-up. In the RST pin
is disabled or if the ISP Fuse is disabled, this is the only method to enter programming (see
“External Reset” on page
Address
0040H
1. Apply power between V
2. Wait at least t
3. Wait at least t
4. Start programming session.
and is preset in the factory. The parameters are read at POR and the device is configured
depend on the current settings of the device.
Parameter Name
RC Oscillator Calibration Byte
Analog Configuration Definitions
PWRUP
SUT
for the internal Power-on Reset to complete. The value of t
. and drive SS high.
126.
26).
CC
and GND pins. RST should remain low.
The RC Calibration Byte controls the frequency of
the internal RC oscillator. The frequency is inversely
proportional to the calibration value such that higher
values result in lower frequencies. A copy of the
factory-set calibration value is stored at location
0008H of the Atmel Signature.
Description
3654A–MICRO–8/09
SUT
will
Table 23-
“Tim-