p87lpc778 NXP Semiconductors, p87lpc778 Datasheet - Page 39

• Manufacturer Part Number: p87lpc778
• Description: Cmos Single-chip 8-bit 80c51 Microcontroller 128-byte Data Ram, 8 Kb Otp
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Table 37:
Table 38:
9397 750 12378
Product data
Oscillator
Frequency
20 kHz
32 kHz
100 kHz
Oscillator
Frequency
100 kHz
1 MHz
4 MHz
Recommended oscillator capacitors for use with the low frequency oscillator option
Recommended oscillator capacitors for use with the medium frequency oscillator option
V
Lower Limit
15 pF
15 pF
15 pF
V
Lower Limit
33 pF
15 pF
15 pF
DD
DD
8.10.1 Low speed oscillator option
8.10.2 Medium speed oscillator option
8.10.3
8.10 Oscillator
= 2.7 V to 4.5 V
= 2.7 V to 4.5 V
Table 36:
The P87LPC778 provides several user selectable oscillator options, allowing
optimization for a range of needs from high precision to lowest possible cost. These
are configured when the EPROM is programmed. Basic oscillator types that are
supported include: low, medium, and high speed crystals, covering a range from
20 kHz to 20 MHz; ceramic resonators; and on-chip RC oscillator.
This option supports an external crystal in the range of 20 kHz to 100 kHz.
This option supports an external crystal in the range of 100 kHz to 4 MHz. Ceramic
resonators are also supported in this configuration.
This option supports an external crystal in the range of 4 MHz to 20 MHz. Ceramic
resonators are also supported in this configuration.
Bit
7
6
5
4
3
2
1
0
High speed oscillator option
Optimal Value
15 pF
15 pF
15 pF
Optimal Value
33 pF
15 pF
15 pF
Symbol
-
-
-
-
-
-
-
-
KBI - Keyboard interrupt register (address 86H) bit description
Rev. 01 — 31 March 2004
Upper Limit
33 pF
33 pF
33 pF
Upper Limit
47 pF
33 pF
33 pF
Description
When set, enables P0.7 as a cause of a Keyboard Interrupt.
When set, enables P0.6 as a cause of a Keyboard Interrupt.
When set, enables P0.5 as a cause of a Keyboard Interrupt.
When set, enables P0.4 as a cause of a Keyboard Interrupt.
When set, enables P0.3 as a cause of a Keyboard Interrupt.
When set, enables P0.2 as a cause of a Keyboard Interrupt.
When set, enables P0.1 as a cause of a Keyboard Interrupt.
When set, enables P0.0 as a cause of a Keyboard Interrupt.
V
Lower Limit
33 pF
33 pF
15 pF
V
Lower Limit
33 pF
15 pF
15 pF
DD
DD
= 4.5 V to 5.5 V
= 4.5 V to 5.5 V
CMOS single-chip 8-bit microcontroller
Optimal Value
33 pF
33 pF
15 pF
Optimal Value
33 pF
22 pF
15 pF
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
P87LPC778
Upper Limit
47 pF
47 pF
33 pF
Upper Limit
47 pF
47 pF
33 pF
39 of 79