Rohm LAPIS SEMICONDUCTOR ML620Q503, User Manual

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ML620Q503/Q504 User's Manual
Chapter 11 Synchronous Serial Port (SSIO)
FEUL620Q504 11–7
11.3 Description of Operation
11.3.1 Transmit Operation
When “1” is written to the S0MD1 bit and “0” is written to the S0MD0 bit of the serial mode register (SIO0MOD), this
LSI is set to a transmit mode.
When transmit data is written to the serial port transmit/receive buffer (SIO0BUF) and the S0EN bit of the serial port
control register (SIO0CON) is set to “1”, transmission starts. When transmission of 8/16-bit data terminates, a
synchronous serial port interrupt (SIO0INT) occurs and the S0EN bit is set to “0”.
Transmit data is output from SOUT0 pin.
When an internal clock is selected in the serial port mode register (SIO0MOD), the LSI is set to a master mode and
when an external clock (SCK0) is selected, the LSI is set to a slave mode.
The serial port mode register (SIO0MOD) enables selection of MSB first/LSB first.
The transmit data output pin (SOUT0) and transfer clock input/output pin (SCK0) must be set to the tertiary functions.
Figures 11-2, 11-3, 11-4 and 11-5 show the transmit operation waveforms of the synchronous serial ports for “clock type
0 and positive-logic”, “clock type 0 and negative-logic”, “clock type 1 and positive-logic” and “clock type 1 and
negative-logic”, respectively (8-bit length, LSB first).
Figure 11-2 Transmit Operation Waveforms of Synchronous Serial Port
for Clock Type 0 (8-bit Length, LSB first, Positive Logic)
Figure 11-3 Transmit Operation Waveforms of Synchronous Serial Port
for Clock Type 0 (8-bit Length, LSB first, Negative Logic)
S0EN
0
1 2 3 4 5 7 6
Transmit data
SCK0
SIO0TRL
SOUT0
SIO0INT
S0EN
0
1 2 3 4 5 7 6
Transmit data
SCK0
SIO0TRL
SOUT0
SIO0INT