HD64F2168 Datasheet, PDF (539/874 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

Time Indication (at Maximum Transfer Rate) [ns]
Item
t
cyc
Indi-
cation
t /t
Sr Sf
Influence
(Max.)
I²C Bus
Specifi-
cation φ =
(Min.) 5 MHz
φ=
8 MHz
φ=
10
MHz
φ=
16
MHz
φ=
20
MHz
φ=
25
MHz
φ=
33
MHz
t
SDAHO
3t
cyc
Standard 0
mode
0
600 375 300 188 150 120 91
High-speed 0
0
600 375 300 188 150 120 91
mode
Notes: 1. Does not meet the I²C bus interface specification. Remedial action such as the following
is necessary: (a) secure a start/stop condition issuance interval; (b) adjust the rise and
fall times by means of a pull-up resistor and capacitive load; (c) reduce the transfer rate;
(d) select slave devices whose input timing permits this output timing.
The values in the above table will vary depending on the settings of the bits TCSS,
IICX5 to IICX0 and CKS0 to CKS2. Depending on the frequency it may not be possible
to achieve the maximum transfer rate; therefore, whether or not the I²C bus interface
specifications are met must be determined in accordance with the actual setting
conditions.
2. Value when the IICXn bit is set to 1. When the IICXn bit is cleared to 0, the value is
(– 6t_cyc) (n = 0 to 5).
3. Calculated using the I²C bus specification values (standard mode: 4700 ns min.; high-
speed mode: 1300 ns min.).
7. Notes on ICDR register read at end of master reception
To halt reception at the end of a receive operation in master receive mode, set the TRS bit to 1
and write 0 to BBSY and SCP in ICCR. This changes SDA from low to high when SCL is
high, and generates the stop condition. After this, receive data can be read by means of an
ICDR read, but if data remains in the buffer the ICDRS receive data will not be transferred to
ICDR, and so it will not be possible to read the second byte of data.
If it is necessary to read the second byte of data, issue the stop condition in master receive
mode (i.e. with the TRS bit cleared to 0). When reading the receive data, first confirm that the
BBSY bit in the ICCR register is cleared to 0, the stop condition has been generated, and the
bus has been released, then read the ICDR register with TRS cleared to 0.
Note that if the receive data (ICDR data) is read in the interval between execution of the
instruction for issuance of the stop condition (writing of 0 to BBSY and SCP in ICCR) and the
actual generation of the stop condition, the clock may not be output correctly in subsequent
master transmission.
Clearing of the MST bit after completion of master transmission/reception, or other
modifications of IIC control bits to change the transmit/receive operating mode or settings,
must be carried out during interval (a) in figure 15.29 (after confirming that the BBSY bit has
been cleared to 0 in the ICCR register).
Rev. 3.00, 03/04, page 499 of 830