Operation - NEC Renesas V850/SC1 User Manual

11.4.4

Operation

CSIn is has the following two operation modes (n = 5, 6).
• Single transfer mode
• Repeat transfer mode
(1) Single transfer mode
(a) Usage
In the receive-only mode (TRMDn bit of CSIMn register = 0), transfer is started by reading
data buffer register (SIRBn/SIRBLn) (n = 5, 6).
In the transmit/receive mode (TRMDn bit of CSIMn register = 1), transfer is started by writing
transmit data buffer register (SOTBn/SOTBLn).
In the slave mode, operation must be enabled beforehand (CSIEn bit of CSIMn register = 1).
When transfer is started, the value of the CSOTn bit of the CSIMn register becomes 1 (transmission
execution status).
Upon transfer completion, the transmission/reception completion interrupt (INTCSIn) is set (1), and the
CSOTn bit is cleared (0). The next data transfer request is then waited for.
Notes 1. When a data length of 16 bits (CCLn bit of CSIMn register = 1) has been set, read the SIRBn
register. When a data length of 8 bits (CCLn bit of CSIMn register = 0) has been set, read the
SIRBLn register.
2. When a data length of 16 bits (CCLn bit of CSIMn register = 1) has been set, write to the
SOTBn register. When a data length of 8 bits (CCLn bit of CSIMn register = 0) has been set,
write to the SOTBLn register.
Caution When the CSOTn bit of the CSIMn register = 1, do not manipulate the CSIn register.
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CHAPTER 11 SERIAL INTERFACE FUNCTION
User's Manual U15109EJ3V0UD
Note 1
the receive
Note 2
to the