M37281EKSP Datasheet, PDF (42/172 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER and ON-SCREEN DISPLAY CONTROLLER

M37281MAH–XXXSP,M37281MFH–XXXSP,M37281MKH–XXXSP, M37281EKSP
8.6.8 START/STOP Condition Detect Conditions
The START/STOP condition detect conditions are shown in
Figure 8.6.11 and Table 8.6.3. Only when the 3 conditions of Table
8.6.3 are satisfied, a START/STOP condition can be detected.
Note: When a STOP condition is detected in the slave mode
(MST = 0), an interrupt request signal “IICIRQ” is generated to the
CPU.
SCL
SDA
(START condition)
SDA
(STOP condition)
SCL release time
Setup
time
Hold time
Setup
time
Hold time
Fig. 8.6.11 START Condition/STOP Condition Detect Timing Dia-
gram
Table 8.6.3 START Condition/STOP Condition Detect Conditions
Standard Clock Mode
6.5 µs (26 cycles) < SCL
release time
3.25 µs (13 cycles) < Setup time
3.25 µs (13 cycles) < Hold time
High-speed Clock Mode
1.0 µs (4 cycles) < SCL
release time
0.5 µs (2 cycles) < Setup time
0.5 µs (2 cycles) < Hold time
Note: Absolute time at φ = 4 MHz. The value in parentheses denotes the num-
ber of φ cycles.
8.6.9 Address Data Communication
There are two address data communication formats, namely, 7-bit
addressing format and 10-bit addressing format. The respective ad-
dress communication formats is described below.
(1) 7-bit Addressing Format
To meet the 7-bit addressing format, set the 10BIT SAD bit of the I²C
control register (address 00F916) to “0.” The first 7-bit address data
transmitted from the master is compared with the high-order 7-bit
slave address stored in the I²C address register (address 00F716).
At the time of this comparison, address comparison of the RBW bit of
the I²C address register (address 00F716) is not made. For the data
transmission format when the 7-bit addressing format is selected,
refer to Figure 8.6.12, (1) and (2).
(2) 10-bit Addressing Format
To meet the 10-bit addressing format, set the 10BIT SAD bit of the
I²C control register (address 00F916) to “1.” An address comparison
is made between the first-byte address data transmitted from the
master and the 7-bit slave address stored in the I²C address register
(address 00F716). At the time of this comparison, an address com-
parison between the RBW bit of the I²C address register (address
__
00F716) and the R/W bit which is the last bit of the address data
transmitted from the master is made. In the 10-bit addressing mode,
__
the R/W bit which is the last bit of the address data not only specifies
the direction of communication for control data but also is processed
as an address data bit.
When the first-byte address data matches the slave address, the
AAS bit of the I²C status register (address 00F816) is set to “1.” After
the second-byte address data is stored into the I²C data shift register
(address 00F616), make an address comparison between the sec-
ond-byte data and the slave address by software. When the address
data of the 2nd bytes matches the slave address, set the RBW bit of
the I²C address register (address 00F716) to “1” by software. This
processing can match the 7-bit slave address and R/W data, which
are received after a RESTART condition is detected, with the value
of the I²C address register (address 00F716). For the data transmis-
sion format when the 10-bit addressing format is selected, refer to
Figure 8.6.12, (3) and (4).
Rev.1.01 2003.07.16 page 42 of 170