
R01UH0336EJ0102 Rev.1.02
Page 1185 of 1538
Jul 17, 2014
V850E2/PG4-L
Section 21 Clocked Serial Interface G (CSIG)
21.3.9
Handshake Function
CSIG features a handshake function to synchronize the master and the slave
devices. This function can be enabled/disabled by bit CSIGnCTL1.CSIGnHSE.
For handshake, the signals CSIGnTRYI/CSIGnTRYO are used.
The timing depends on the data phase selection bit CSIGnCFG0.CSIGnDAP.
(1)
Slave Mode
When CSIGnCTL1.CSIGnHSE = 1, the slave outputs CSIGnTRYO = 0 when it
is busy. This happens when previously received data is still in the CSIGnRX0
register, and new data cannot be copied from the shift register to CSIGnRX0
(CSIGnRX0 full condition).
The following examples assume 8-bit data length.
Figure 21-15
Ready/Busy Signal from Slave (CSIGnCFG0.CSIGnDAP = 0)
As long as the slave is busy, the master has to wait (i.e. suspend the
transmission clock). The slave sets CSIGnTRYO to high (“ready”) as soon as
the reception register CSIGnRX0 has been read.
Figure 21-16
Ready/Busy Signal from Slave (CSIGnCFG0.CSIGnDAP = 1)
DAP = 0
DO7
DO6
DO5
DO2
DO1
DO0
DI7
DI6
DI5
Busy
DI2
DI1
DI0
CSIGnRX0 holds previous data
Receive shift register holds new data
Read previous data from CSIGnRX0
CSIGnTSCK
CSIGnTSI
CSIGnTSO
CSIGnTRYO
CSIGnTIR
DAP = 1
DO7
DO6
DO5
DO2
DO1
DO0
DI7
DI6
DI5
Busy
DI2
DI1
DI0
CSIGnRX0 holds previous data
Recive shift register holds new data
Read previous data from CSIGnRX0
CSIGnTSCK
CSIGnTSI
CSIGnTSO
CSIGnTRYO
CSIGnTIR
Содержание V850 Series
Страница 1556: ...V850E2 PG4 L R01UH0336EJ0102 Back Cover ...