參數(shù)資料
型號(hào): PCF8584
廠商: NXP Semiconductors N.V.
英文描述: IIC-bus controller(IIC總線控制器)
中文描述: IIC總線控制器(國際進(jìn)口總線控制器)
文件頁數(shù): 8/40頁
文件大?。?/td> 224K
代理商: PCF8584
1997 Oct 21
8
Philips Semiconductors
Product specification
I
2
C-bus controller
PCF8584
6.3
Set-up registers S0', S2 and S3
Registers S0', S2 and S3 are used for initialization of the
PCF8584 (see Fig.5 ‘Initialization sequence’ flowchart).
6.4
Own address register S0'
When the PCF8584 is addressed as slave, this register
must be loaded with the 7-bit I
2
C-bus address to which the
PCF8584 is to respond. During initialization, the own
address register S0' must be written to, regardless
whether it is later used. The Addressed As Slave (AAS) bit
in status register S1 is set when this address is received
(the value in S0 is compared with the value in S0'). Note
that the S0 and S0' registers are offset by one bit; hence,
programming the own address register S0' with a value of
55H will result in the value AAH being recognized as the
PCF8584’s slave address (see Fig.1).
Programming of S0' is accomplished via the parallel-bus
when A0 is LOW, with the appropriate bit combinations set
in control status register S1 (S1 is written when
pin A0 = HIGH). Bit combinations for accessing all
registers are given in Table 5. After reset, S0' has default
address 00H (PCF8584 is thus initially in monitor mode,
see Section 6.12.3).
6.5
Clock register S2
Register S2 provides control over chip clock frequency
and SCL clock frequency. S20 and S21 provide a selection
of 4 different I
2
C-bus SCL frequencies which are shown in
Table 2. Note that these SCL frequencies are only
obtained when bits S24, S23 and S22 are programmed to
the correct input clock frequency (f
clk
).
Table 2
Register S2 selection of SCL frequency
S22, S23 and S24 are used for control of the internal clock
prescaler. Due to the possibility of varying microcontroller
clock signals, the prescaler can be programmed to adapt
to 5 different clock rates, thus providing a constant internal
clock. This is required to provide a stable time base for the
SCL generator and the digital filters associated with the
I
2
C-bus signals SCL and SDA. Selection for adaption to
external clock rates is shown in Table 3.
BIT
APPROXIMATE SCL
FREQUENCY f
SCL
(kHz)
S21
S20
0
0
1
1
0
1
0
1
90
45
11
1.5
Programming of S2 is accomplished via the parallel-bus
when A0 = LOW, with the appropriate bit combinations set
in control status register S1 (S1 is written when
A0 = HIGH). Bit combinations for accessing all registers
are given in Table 5.
Table 3
Register S2 selection of clock frequency
Note
1.
X = don’t care.
6.6
Interrupt vector S3
The interrupt vector register provides an 8-bit
user-programmable vector for vectored-interrupt
microcontrollers. The vector is sent to the bus port
(DB7 to DB0) when an interrupt acknowledge signal is
asserted and the ENI (enable interrupt) flag is set. Default
vector values are:
Vector is ‘00H’ in 80XX mode
Vector is ‘0FH’ in 68000 mode.
On reset the PCF8584 is in the 80XX mode, thus the
default interrupt vector is ‘00H’.
6.7
Data shift register/read buffer S0
Register S0 acts as serial shift register and read buffer
interfacing to the I
2
C-bus. All read and write operations
to/from the I
2
C-bus are done via this register. S0 is a
combination of a shift register and a data buffer; parallel
data is always written to the shift register, and read from
the data buffer. I
2
C-bus data is always shifted in or out of
shift register S0.
INTERNAL CLOCK FREQUENCY
S24
S23
X
(1)
0
0
1
1
S22
X
(1)
0
1
0
1
f
clk
(MHz)
3
4.43
6
8
12
0
1
1
1
1
相關(guān)PDF資料
PDF描述
PCF8593 Low power clock/calendar(低功耗時(shí)鐘/日歷)
PCF8801 CRYSTAL RESONATOR, 6MHZ
PCF8801U LCD driver for 140 x 2 segments
PCF8811 80 x 128 pixels matrix LCD driver
PCF8812 CRYSTAL, 8.0 MHZ
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PCF8584P 制造商:NXP Semiconductors 功能描述:I2C Bus Controller 20-Pin PDIP Bulk
PCF8584P,112 功能描述:I2C 接口集成電路 PARALLEL TO I2C CONVERTER RoHS:否 制造商:NXP Semiconductors 電源電壓-最大:5.5 V 電源電壓-最小:2.3 V 最大工作頻率:400 KHz 最大工作溫度:+ 85 C 封裝 / 箱體:TSSOP-16
PCF8584P112 制造商:NXP Semiconductors 功能描述:PARALLEL TO I2C BUS INTERFACE 8584 制造商:NXP Semiconductors 功能描述:IC I2C CONTROLLER DIP-20
PCF8584PN 制造商:未知廠家 制造商全稱:未知廠家 功能描述:I/O Port
PCF8584T 制造商:NXP Semiconductors 功能描述: 制造商:Texas Instruments 功能描述: 制造商:NXP Semiconductors 功能描述:I2C Bus Controller 20-Pin SO 制造商:PHILIPS-SEMI 功能描述: