參數(shù)資料
型號(hào): VPX3224D
廠商: Electronic Theatre Controls, Inc.
英文描述: Video Pixel Decoders
中文描述: 視頻解碼器像素
文件頁數(shù): 35/92頁
文件大?。?/td> 672K
代理商: VPX3224D
VPX 3225D, VPX 3224D
PRELIMINARY DATA SHEET
35
Micronas
2.14. Control Interface
2.14.1. Overview
Communication between the VPX and the external con-
troller is performed serially via the I
2
C bus (pins SCL and
SDA).
There are basically two classes of registers in the VPX.
The first class of registers are the directly addressable
I
2
C registers. These are registers embedded directly in
the hardware. Data written to these registers is inter-
preted combinatorially directly by the hardware. These
registers are all a maximum of 8-bits wide.
The second class of registers are the ‘FP-RAM regis-
ters’, the memory of the onboard microcontroller (Micro-
nas Fast Processor). Data written into this class of regis-
ters is read and interpreted by the FP’s micro-code.
Internally, these registers are 12 bits wide. Communica-
tions with these registers require I
2
C packets with 16-bit
data payloads.
Communication with both classes of registers (I
2
C and
FP-RAM) is performed via I
2
C. The format of the I
2
C
telegram depends on which type of register is being ad-
dressed.
2.14.2. I
2
C Bus Interface
The VPX has an I
2
C bus slave interface and uses I
2
C
clock synchronization to slow down the interface if re-
quired. The I
2
C bus interface uses one level of subad-
dressing. First, the bus address selects the IC, then a
subaddress selects one of the internal registers.
FP
controller
Read Address
Write Address
Data
Status
I
2
C
subaddress
space
0
FP-RAM
0
Fig. 2–39:
FP register addressing
ff
17f
The I
2
C interface of the VPX conforms to the I
2
C bus
specification for the fast-mode. It incorporates slope
control for the falling edges of the SDA and SCL signals.
If the power supply of the VPX is switched off, both pins
SCL and SDA float. External pull-up devices must be
adapted to fulfill the required rise time for the fast-mode.
For bus loads up to 200 pF, the pull-up device could be
a resistor; for bus loads between 200 pF and 400 pF, the
pull-up device can be a current source (3 mA max.) or
a switched resistor circuit.
2.14.3. Reset and I
2
C Device Address Selection
The VPX can respond to one of two possible chip ad-
dresses. The address selection is made at reset by an
externally supplied level on the OE pin. This level is
latched on the inactive going edge of RES.
Table 2–15:
I
2
C bus device addresses
OE
A6
A5
A4
A3
A2
A1
A0
R/W
hex
0
1
0
0
0
0
1
1
1/0
86/87
1
1
0
0
0
1
1
1
1/0
8e/8f
2.14.4. Protocol Description
Once the reset is complete, the IC is selected by assert-
ing the device address in the address part of a I
2
C trans-
mission. A device address pair is defined as a write ad-
dress (86 hex or 8e hex) and a read address (87 hex or
8f hex). Writing is done by sending the device write ad-
dress first, followed by the subaddress byte and one or
two data bytes. For reading, the read subaddress has to
be transmitted, first, by sending the device write address
(86 hex or 8e hex) followed by the subaddress, a second
start condition with the device read address (87 hex or
8f hex), and reading one or two bytes of data. It is not al-
lowed to send a stop condition in between. This will re-
sult in reading erratic data.
The registers of the VPX have 8 or 16 bit data size; 16-bit
registers are accessed by reading/writing two 8-bit data
bytes with the high byte first. The order of the bits in a
data/address/subaddress byte is always MSB first.
Figure 2–40 shows I
2
C bus protocols for read and write
operations of the interface; the read operation requires
an extra start condition after the subaddress and repeti-
tion of the read chip address, followed by the read data
bytes. The following protocol examples use device ad-
dress hex 86/87.
相關(guān)PDF資料
PDF描述
VPX3224E Video Pixel Decoders
VPX322XE Video Pixel Decoders
VQ1000J N-Channel Enhancement-Mode MOSFET Transistor(最小漏源擊穿電壓60V,夾斷電流0.225A的N溝道增強(qiáng)型MOSFET晶體管)
VQ1000J N-Channel 60-V (D-S) MOSFET
VQ1001J Dual N-Channel 30-V (D-S) MOSFET with Schottky Diode
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
VPX3224D-C3 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Microprocessor
VPX3224E 制造商:MICRONAS 制造商全稱:MICRONAS 功能描述:Video Pixel Decoders
VPX3225D 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Video Pixel Decoders
VPX3225D-C3 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Microprocessor
VPX3225E 制造商:MICRONAS 制造商全稱:MICRONAS 功能描述:Video Pixel Decoders