FS401LF ETC2 [List of Unclassifed Manufacturers], FS401LF Datasheet - Page 87

• Manufacturer Part Number: FS401LF
• Description: PC to TV Video Scan Converters
• Manufacturer: ETC2 [List of Unclassifed Manufacturers]

FS401, FS403
There are five steps within a serial bus cycle:
1. Start signal
2. Slave address byte
3. Pointer register address byte
4. Data byte to read or write
5. Stop signal
When the serial interface is inactive (SIOCLK = H and SIODATA = H) communications are initiated by
sending a start signal. The start signal (Figure 16, left waveform) is a HIGH-to-LOW transition on
SIODATA while SIOCLK is HIGH. This signal alerts all slaved devices that a data transfer sequence is
imminent.
For 7-bit addressing, the first eight bits of data transferred after a start signal comprise a seven bit slave
address and a single R/W bit (Read = H, Write = L). As shown in Figure 17, the R/W bit indicates the
direction of data transfer, read from or write to the slave device. If the transmitted slave address matches
the address of the FS400 (set by the state of the SIOA
Addresses, the FS400 acknowledges by bringing SIODATA LOW on the 9th SIOCLK pulse (see Figure
18). If the addresses do not match, the FS400 does not acknowledge.
With 10-bit addressing (see Figure 19 and Figure 20), data is still transferred in 8-bit chunks. The upper
two bits of the ten bit address are transferred as the lower two bits of the first byte along with the reserved
sequence 11110 in the upper five bits and the R/W bit. The lower eight bits are transferred in the second
byte without a R/W bit. Subsequent data reads or writes follow the 7-bit transfer sequences.
For each byte of data read or written, the MSB is the first bit of the sequence.
JANUARY 24, 2007
SDA
SDA
SCL
SCL
ACK0
1
A7
1
A6
Figure 18. 7-bit Slave Address with Read/Write\ Bit
Figure 20. 10-bit address transfer, lower eight bits
Figure 19. 10-bit address transfer, upper two bits
1
A5
1
A4
0
A3
87
0
and SIOA
A9
A2
COPYRIGHT © 1999 FOCUS ENHANCEMENTS, INC.
A8
10/7
A1
input pins in Table 5. Serial Port
R/W
A0
ACK0
PRODUCT SPECIFICATION
ACK1
REV. NO. 1.7