NEC V850E/MS1 UPD703100, User Manual

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CHAPTER 10 SERIAL INTERFACE FUNCTION
User’s Manual U12688EJ4V0UM00
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10.3 Clocked Serial Interfaces 0 to 3 (CSI0 to CSI3)
10.3.1 Features
{
High transfer rate Max. 10 Mbps (when the internal system clock is operating at 40 MHz)
…
µ
PD703100-40, 703100A-40
Max. 8.25 Mbps (when the internal system clock is operating at 33 MHz)
… other than above
{
Half-duplex communications
{
Character length: 8 bits
{
It is possible to switch MSB first or LSB first for data.
{
Either external serial clock input or internal serial clock output can be selected.
{
3-wire type SOn: Serial data output
SIn: Serial data input
SCKn: Serial clock input/output
{
Interrupt source 1 type
•
Transmission/reception complete interrupt (INTCSIn)
Remark n = 0 to 3
10.3.2 Configuration
CSIn are controlled by the clocked serial interface mode registers (CSIMn). Transmission/reception data can be
read from and written to the SIOn registers (n = 0 to 3).
(1) Clocked serial interface mode registers (CSIM0 to CSIM3)
The CSIMn registers are 8-bit registers that specify CSIn operations.
(2) Serial I/O shift registers (SIO0 to SIO3)
The SIOn registers are 8-bit registers that convert serial data to parallel data. SIOn is used for both
transmission and reception.
Data is shifted in (received) or shifted out (transmitted) either from the MSB side or the LSB side.
Actual transmitting/receiving operations are controlled by reading from or writing to SIOn.
(3) Selector
This selects the serial clock to be used.
(4) Serial clock controller
This performs control of supply to the serial clock shift register. Also, when the internal clock is used, it
controls the clock that outputs to the SCKn pin.