MITSUBISHI MICROCOMPUTERS
4280 Group
SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER for INFRARED REMOTE CONTROL TRANSMITTERS
(2) Functional outline
In the first transfer, the command code is input. Then, address
input or data input/output is performed according to the
contents of the command code. Table 11 shows the software
command used in the PROM mode. The following explains
each software command.
In the PROM mode, data is transferred with the clock-
synchronous serial input/output. The input data is read through
the SDA pin into the internal circuit synchronously with the
rising edge of the serial clock pulse. The output data is output
from the SDA pin synchronously with the falling edge of the
serial clock pulse. Data is transferred in units of 8 bits.
Table 11 Software command
Number of transfer
Command
First command
code input
1516
Second
Third
Fourth
Read
Read address L (input)
Read address H (input)
Read data L (output)
Program data L (input)
Program data L (input)
Program
2516
Program address L (input) Program address H (input)
Program address L (input) Program address H (input)
Program verify
3516
Number of transfer
Command
Fifth
Sixth
Seventh
Read
Read data H (output)
Program data H (input)
Program data H (input)
Program
Program verify
Verify data L (output)
Verify data H (output)
(3) Read
When the PGM pin is released back to “H” and serial clock is
input to the SCLK pin, the low-order 8 bits and high-order 8
bits of read data which have been stored into the data latch,
are serially output from the SDA pin.
Input the command code 1516 in the first transfer. Proceed
and input the low-order 8 bits and the high-order 8 bits of the
address and pull the PGM pin to “L.” When this is done, the
contents of input address is read and stored into the internal
data latch.
tCH
tCH
tCH
SCLK
SDA
D0
D7
D8
A8 A9
A0
A7
0
0 0 0 0
0
0 0 0 0 0 0 0
1
0 1 0 1 0 0 0
Command code
input (1516)
Read address
input (L)
Read address
input (H)
Read data output
(L)
Read data output
(H)
tCR
tWR
tRC
PGM
Read
Note: When outputting the read data, the SDA pin is switched for output at the first falling of the serial clock. The SDA pin is
placed in the high-impedance state during the th(C–E) period after the last rising edge of the serial clock (at the 16th bit).
Fig. 28 Timing at reading
MITSUBISHI
ELECTRIC
41
MITSUBISHI [ Mitsubishi Group ]
