HD4074329S Renesas Electronics America, HD4074329S Datasheet - Page 57

• Manufacturer Part Number: HD4074329S
• Description: MCU 4-Bit HMCS400 CISC 20KB EPROM 3.3V/5V 64-Pin SDIP
• Manufacturer: Renesas Electronics America

Specifications of HD4074329S

• Package: 64SDIP
• Family Name: HMCS400
• Maximum Speed: 4.5 MHz
• Ram Size: 268 Byte
• Program Memory Size: 20 KB
• Operating Supply Voltage: 3.3|5 V
• Data Bus Width: 4 Bit
• Program Memory Type: EPROM
• Number Of Programmable I/os: 35
• On-chip Adc: 4-chx8-bit
• Operating Temperature: -20 to 75 °C
• Number Of Timers: 3

Selecting and Changing Operating Mode: Table 28 lists the serial interface’s operating modes. To
select an operating mode, use one of these combinations of PMR and SMR settings; to change the
operating mode, always initialize the serial interface internally by writing data to the SMR.
Table 28
SMR
Bit 3
1
Serial Interface Operation: Three operating modes are provided for the serial interface; transitions
between them are shown in figure 32.
In STS wait state, the serial interface is initialized and the transmit clock is ignored. If the STS instruction
is then executed, the serial interface enters transmit clock wait state.
In transmit clock wait state, input of the transmit clock increments the octal clock, shifts the serial clock
register, and activates serial transmission. However, note that if clock output mode is selected, the transmit
clock is continuously output but data is not transmitted.
During transfer state, the input of eight clocks or the execution of the STS instruction sets the octal counter
to 000, and the serial interface enters transmit clock wait state. If the state changes from transmit to another
state, the serial interrupt request flag is set by the octal counter reaching 000.
In this state, if the internal clock has been selected, the transmit clock is output in answer to the execution
of the STS instruction, but serial transmission is inhibited after the eighth clock is output.
Transmit clock
Serial input data
latch timing
Serial output
data
Serial Interface Operating Modes
Bit 1
0
1
PMRA
Bit 0
0
1
0
1
LSB
Figure 31 Timing of Serial Interface Output
1
2
Operating Mode
Continuous clock output mode
Transmit mode
Receive mode
Transmit/receive mode
3
4
5
6
HD404328 Series
7
MSB
8
53