TC9446FG Datasheet, PDF (14/41 Pages) Toshiba Semiconductor – Audio Digital Processor for Decode of Dolby Digital (AC-3), MPEG2 Audio

2-2. I²C Mode Setting
TC9446FG
2-2-1. Data Transmission Format in I²C Mode
The foundations of a data transmission format in the I²C mode are shown in Figure 7.
Fundamentally, the data transmission at the time of the I²C mode checks that ACK bit is set to “L”, after making I²C Address (write = 3Ah) to transmission.
However, at the time of “H”, ACK bit performs Start Condition again, without performing STOP Condition, and transmits I²C Address (3Ah). I²C Transmit 24
bit command after Address transmission.
And, at the time of data Write of TC9446FG, Write of 24 bit data of the number (1-16 word) of words set up by 24 bit command is performed from a MCU, and,
finally, END Condition is transmitted.
Moreover, it checks that transmit I²C Address (read = 3Bh) from TC9446FG at the time of Read to a MCU, without performing END Condition after 24 bit
command transmission, and ACK bit is set to “L”.
However, at the time of “H”, ACK bit performs Start Condition again, without performing STOP Condition, and transmits I²C Address (3Bh).
The word set up by 24 bit command after checking that ACK bit is “L”. Although Read of 24 bit data of a number (1-16 word) is performed, as for the inside of
Read, a MCU needs to set ACK bit to “L” for every 8-bit Read data.
And, only ACK bit added to the last 8 bits is set to “H”, and STOP Condition is transmitted.
Moreover, at the time of transmission of only a 24 bit command which does not perform R/W of data, END Condition is transmitted after 24 bit command
transmission.
In addition, in TC9446FG, polling of the access demand from a MCU is carried out every about 6 ms at the time of decode processing. Therefore, R/W of data
from a MCU need to be performed at the interval of 6 ms or more.
At the time of Write-in, Read-out and a command only shows the transmission format to Figure 7 to Figure 10.
SDA
SCL
I²C Address (3Ah) R/W ACK
I²C Address
DATA Hi (8 bit)
ACK
DATA Mid (8 bit) ACK
24 bit DATA (1 word to 16 word)
DATA Lo (8 bit)
ACK
START Condition
Figure 7 Data Transmission Format in the I²C Mode
STOP Condition
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2005-09-28