P87C660X2 PHILIPS [NXP Semiconductors], P87C660X2 Datasheet - Page 33

• Manufacturer Part Number: P87C660X2
• Description: 80C51 8-bit microcontroller family
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
SIO1 Implementation and Operation: Figure 17 shows how the
on-chip I
describes the individual blocks.
I
The input filters have I
is less than 1.5 V, the input logic level is interpreted as 0; if the input
voltage is greater than 3.0 V, the input logic level is interpreted as 1.
Input signals are synchronized with the internal clock (f
spikes shorter than three oscillator periods are filtered out.
The output stages consist of open drain transistors that can sink
3 mA at V
clamping diodes to V
bus and V
A
This 8-bit special function register may be loaded with the 7-bit slave
address (7 most significant bits) to which SIO1 will respond when
programmed as a slave transmitter or receiver. The LSB (GC) is
used to enable general call address (00H) recognition.
2003 Oct 02
NPUT
DDRESS
80C51 8-bit microcontroller family
RAM, low voltage (2.7 to 5.5 V), low power, high speed (30/33
MHz), two 400KB I
F
ILTERS AND
2
R
C bus interface is implemented, and the following text
OUT
DD
EGISTER,
is switched off, the I
< 0.4 V. These open drain outputs do not have
O
S
UTPUT
DD
1
2
ADR
C compatible input levels. If the input voltage
. Thus, if the device is connected to the I
2
C interfaces
S
TAGES
2
C bus is not affected.
16 KB OTP/ROM, 512B
OSC
/4), and
2
C
33
C
The comparator compares the received 7-bit slave address with its
own slave address (7 most significant bits in S1ADR). It also
compares the first received 8-bit byte with the general call address
(00H). If an equality is found, the appropriate status bits are set and
an interrupt is requested.
S
This 8-bit special function register contains a byte of serial data to
be transmitted or a byte which has just been received. Data in
S1DAT is always shifted from right to left; the first bit to be
transmitted is the MSB (bit 7) and, after a byte has been received,
the first bit of received data is located at the MSB of S1DAT. While
data is being shifted out, data on the bus is simultaneously being
shifted in; S1DAT always contains the last byte present on the bus.
Thus, in the event of lost arbitration, the transition from master
transmitter to slave receiver is made with the correct data in S1DAT.
HIFT
OMPARATOR
R
EGISTER,
S
1
DAT
P8xC660X2/661X2
Product data