M37221M6_03 Datasheet, PDF (26/62 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER with ON-SCREEN DISPLAY CONTROLLER

MITSUBISHI MICROCOMPUTERS
M37221M6-XXXSP
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER
with ON-SCREEN DISPLAY CONTROLLER
When the first-byte address data matches the slave address, the
AAS bit of the I²C status register (address 00D916) is set to “1.” After
the second-byte address data is stored into the I²C data shift register
(address 00D716), make an address comparison between the sec-
ond-byte data and the slave address by software. When the address
data of the 2nd byte matches the slave address, set the RBW bit of
the I²C address register (address 00D816) 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 00D816). For the data transmis-
sion format when the 10-bit addressing format is selected, refer to
Figure 22, (3) and (4).
(10) Example of Master Transmission
An example of master transmission in the standard clock mode, at
the SCL frequency of 100 kHz and in the ACK return mode is shown
below.
Œ Set a slave address in the high-order 7 bits of the I²C address
register (address 00D816) and “0” in the RBW bit.
 Set the ACK return mode and SCL = 100 kHz by setting “8516” in
the I²C clock control register (address 00DB16).
Ž Set “1016” in the I²C status register (address 00D916) and hold
the SCL at the “H” level.
 Set a communication enable status by setting “4816” in the I²C
control register (address 00DA16).
 Set the address data of the destination of transmission in the high-
order 7 bits of the I²C data shift register (address 00D716) and set
“0” in the least significant bit.
‘ Set “F016” in the I²C status register (address 00D916) to generate
a START condition. At this time, an SCL for 1 byte and an ACK
clock automatically occurs.
’ Set transmit data in the I²C data shift register (address 00D716).
At this time, an SCL and an ACK clock automatically occurs.
“ When transmitting control data of more than 1 byte, repeat step
’.
” Set “D016” in the I²C status register (address 00D916). After this,
if ACK is not returned or transmission ends, a STOP condition
occurs.
(11) Example of Slave Reception
An example of slave reception in the high-speed clock mode, at the
SCL frequency of 400 kHz, in the ACK non-return mode and using
the addressing format is shown below.
Œ Set a slave address in the high-order 7 bits of the I²C address
register (address 00D816) and “0” in the RBW bit.
 Set the no ACK clock mode and SCL = 400 kHz by setting “2516”
in the I²C clock control register (address 00DB16).
Ž Set “1016” in the I²C status register (address 00D916) and hold
the SCL at the “H” level.
 Set a communication enable status by setting “4816” in the I²C
control register (address 00DA16).
 When a START condition is received, an address comparison is
made.
‘ •When all transmitted addresses are “0” (general call)
AD0 of the I²C status register (address 00D916) is set to “1” and
an interrupt request signal occurs.
•When the transmitted addresses match the address set in Œ
AAS of the I²C status register (address 00D916) is set to “1” and
an interrupt request signal occurs.
•In the cases other than the above
AD0 and AAS of the I²C status register (address 00D916) are
set to “0” and no interrupt request signal occurs.
’ Set dummy data in the I²C data shift register (address 00D716).
“ When receiving control data of more than 1 byte, repeat step ’.
” When a STOP condition is detected, the communication ends.
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