P89LV51RD2BBC NXP Semiconductors, P89LV51RD2BBC Datasheet - Page 60

• Manufacturer Part Number: P89LV51RD2BBC
• Description: MCU 8-Bit 89LV 80C51 CISC 64KB Flash 3.3V 44-Pin TQFP Tray
• Manufacturer: NXP Semiconductors

Specifications of P89LV51RD2BBC

• Package: 44TQFP
• Device Core: 80C51
• Family Name: 89LV
• Maximum Speed: 40 MHz
• Ram Size: 1 KB
• Program Memory Size: 64 KB
• Operating Supply Voltage: 3.3 V
• Data Bus Width: 8 Bit
• Program Memory Type: Flash
• Number Of Programmable I/os: 32
• Interface Type: SPI/UART
• Operating Temperature: 0 to 70 °C
• Number Of Timers: 3

NXP Semiconductors
P89LV51RB2_RC2_RD2_5
Product data sheet
Fig 27. Oscillator characteristics
On-chip oscillator
6.13.1 Clock input options and recommended capacitor values for oscillator
6.13.2 Clock doubling option
C 2
C 1
6.13 System clock and clock options
Shown in
amplifier, which can be configured for use as an on-chip oscillator.
When driving the device from an external clock source, XTAL2 should be left disconnected
and XTAL1 should be driven.
At start-up, the external oscillator may encounter a higher capacitive load at XTAL1 due to
interaction between the amplifier and its feedback capacitance. However, the capacitance
will not exceed 15 pF once the external signal meets the V
Crystal manufacturer, supply voltage, and other factors may cause circuit performance to
differ from one application to another. C1 and C2 should be adjusted appropriately for
each design.
frequencies.
Table 57.
More specific information about on-chip oscillator design can be found in the FlashFlex51
Oscillator Circuit Design Considerations application note.
By default, the device runs at 12 clocks per machine cycle (X1 mode). The device has a
clock doubling option to speed up to 6 clocks per machine cycle (see
double mode can be enabled either by an external programmer or using IAP. When set,
the EDC bit in FST register will indicate 6-clock mode.
The clock double mode is only for doubling the internal system clock and the internal flash
memory, i.e. EA = 1. To access the external memory and the peripheral devices, careful
consideration must be taken. Also note that the crystal output (XTAL2) frequency will not
be doubled.
Crystal
Quartz
Ceramic
XTAL2
XTAL1
V
SS
Figure 27
Recommended values for C1 and C2 by crystal type
Table 57
002aaa545
Rev. 05 — 15 December 2009
are the input and output (XTAL1, XTAL2) of an internal inverting
shows the typical values for C1 and C2 vs. crystal type for various
P89LV51RB2/RC2/RD2
External clock drive
C1 = C2
20 pF to 30 pF
40 pF to 50 pF
8-bit microcontrollers with 80C51 core
oscillator
external
signal
n.c.
IL
and V
002aaa546
XTAL2
XTAL1
V
IH
SS
specifications.
Table
© NXP B.V. 2009. All rights reserved.
58). Clock
60 of 76