ch7009a ETC-unknow, ch7009a Datasheet - Page 19

• Manufacturer Part Number: ch7009a
• Description: Chrontel Ch7009 Dvi / Tv Output Device
• Manufacturer: ETC-unknow

CHRONTEL
Transfer Protocol
Both read and write cycles can be executed in “Alternating” and “Auto-increment” modes.
expects a register address prior to each read or write from that location (i.e., transfers alternate between address and
data). Auto-increment mode allows you to establish the initial register location, then automatically increments the
register address after each subsequent data access (i.e., transfers will be address, data...). A basic serial port transfer
protocol is shown in Figure 9 and described below.
1. The transfer sequence is initiated when a high-to-low transition of SD occurs while SC is high; this is the
2. The transfer sequence is terminated when a low-to-high transition of SD occurs while SC is high; this is the
3. Upon receiving the first START condition, the CH7009 expects a Device Address Byte (DAB) from the
4. After the DAB is received, the CH7009 expects a Register Address Byte (RAB) from the master. The
Device Address Byte (DAB)
R/W
Register Address Byte (RAB)
201-0000-035 Rev 1.1, 5/8/2000
“START” condition. Transitions of address and data bits can only occur while SC is low.
“STOP” condition.
master device. The value of the device address is shown in the DAB data format below.
format of the RAB is shown in the RAB data format below (note that B7 is not used).
SD
SC
B7
B7
1
1
Condition
Start
AR[6]
B6
B6
1
Read/Write Indicator
“0”:
“1”:
Device ID
CH7009
master device will write to the CH7009 at the register location specified by the address
AR[6:0]
master device will read from the CH7009 at the register location specified by the
address AR[6:0].
R/W*
AR[5]
Figure 9: Serial Port Transfer Protocol
B5
B5
8
I
1
2
C
acknowledge
CH7009
ACK
9
AR[4]
B4
B4
0
Data
1 - 8
1
acknowledge
ACK
CH7009
AR[3]
B3
B3
9
1
AR[2]
Data n
B2
B2
1 - 8
0
acknowledge
CH7009
ACK
9
AR[1]
B1
B1
1
Alternating mode
CH7009A
Condition
AR[0]
R/W
B0
B0
Stop
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