Figure 12-37: Repeat Transfer (Receive-Only) Timing Chart - NEC V850E/CA1 ATOMIC Preliminary User's Manual

(2) Repeat transfer mode
(a) Usage (receive-only)
<1> Set the repeat transfer mode (AUTO bit of CSIMn register = 1) and the receive-only mode
(TRMD bit of CSIMn register = 0).
<2> Read SIRBn register (start transfer with dummy read).
<3> Wait for transmission/reception completion interrupt request (INTCSIn).
<4> When the transmission/reception completion interrupt request (INTCSIn) has been set to (1),
read the SIRBn register
<5> Repeat steps <3> and <4> (n - 2) times (n: number of transfer data).
<6> Following output of the last transmission/reception completion interrupt request (INTCSIn),
read the SIRBn register and the SIOn register
Note: When transferring n number of data, receive data is loaded by reading the SIRBn register from
the first data to the (n - 2)-th data. The (n-1)-th data is loaded by reading the SIRBEn register,
and the n-th (last) data is loaded by reading the SIOn register.

Figure 12-37: Repeat Transfer (Receive-Only) Timing Chart

SCKn (input/output)
SIn (input)
SIOLn
register
SIRBLn
register
Reg_RD
CSOT bit
INTCSIn
interrupt
SOn (output) L
rq_clr
trans_rq
<1> <2>
Remarks: 1. n = 0, 1
2. Reg_RD:Internal signal. This signal indicates that the receive data buffer register
(SIRBn/SIRBLn) has been read.
rq_clr: Internal signal. Transfer request clear signal.
trans_rq: Internal signal. Transfer request signal.
In the case of the repeat transfer mode, two transfer requests are set at the start of the first transfer.
Following the transmission/reception completion interrupt request (INTCSIn), transfer is continued if
the SIRBn register can be read within the next transfer reservation period. If the SIRBn register can-
not be read, transfer ends and the SIRBn register does not receive the new value of the SIOn regis-
ter.
The last data can be obtained by reading the SIOn register following completion of the transfer.
Chapter 12 Serial Interface Function
Note
(reserve next transfer).
din-1 din-2
din-1
SIRBn (dummy) SIRBn (d1)
<3> <4>
Period during
which next transfer
can be reserved
Preliminary User's Manual U14913EE1V0UM00
Note
.
din-3
din-2 din-3
SIRBn (d2)
<3> <4> <3>
<5>
din-4 din-5
din-4
SIRBn (d3)
<4> <
6>
din-5
SIRBEn (d4)
SIOn (d5)
359