15 Quad Synchronous Serial Interface (QSPI)
S1C31D50/D51 TECHNICAL MANUAL
Seiko Epson Corporation
15-27
(Rev. 2.00)
Data reception
End
Read receive data from
the QSPI_nRXD register
NO
YES
Receive data remained?
Wait for an interrupt request
(QSPI_nINTF.RBFIF = 1)
Data transmission
End
Read the QSPI_nINTF.TBEIF bit
Write transmit data to
the QSPI_nTXD register
YES
NO
NO
YES
Transmit data remained?
QSPI_nINTF.TBEIF = 1 ?
Wait for an interrupt request
(QSPI_nINTF.TBEIF = 1)
Figure 15.5.9.2 Data Transfer Flowcharts in Slave Mode
15.5.10 Terminating Data Transfer in Slave Mode
A procedure to terminate data transfer in slave mode is shown below.
1. Wait for an end-of-transmission interrupt (QSPI_
n
INTF.TENDIF bit = 1). Or determine end of transfer via the
received data.
2. Set the QSPI_
n
CTL.MODEN bit to 0 to disable the QSPI Ch.
n
operations.
15.6 Interrupts
The QSPI has a function to generate the interrupts shown in Table 15.6.1.
Table 15.6.1 QSPI Interrupt Function
Interrupt
Interrupt flag
Set condition
Clear condition
End of transmission QSPI_nINTF.TENDIF When the QSPI_nINTF.TBEIF bit = 1 after data
of the specified bit length (defined by the QSPI_
nMOD.CHLN[3:0] bits) has been sent
Writing 1
Receive buffer full
QSPI_nINTF.RBFIF When data of the specified bit length is received
and the received data is transferred from the shift
register to the received data buffer
Reading of the
QSPI_nRXD
register
Transmit buffer empty QSPI_nINTF.TBEIF When transmit data written to the transmit data
buffer is transferred to the shift register
Writing to the
QSPI_nTXD register
Overrun error
QSPI_nINTF.OEIF
When the receive data buffer is full (when the re-
ceived data has not been read) at the point that
receiving data to the shift register has completed
Writing 1
The QSPI provides interrupt enable bits corresponding to each interrupt flag. An interrupt request is sent to the
CPU core only when the interrupt flag, of which interrupt has been enabled by the interrupt enable bit, is set. For
more information on interrupt control, refer to the “Interrupt” chapter.
The QSPI_
n
INTF register also contains the BSY and MMABSY bits that indicate the QSPI operating status in
register access and memory mapped access modes, respectively. Figure 15.6.1 shows the QSPI_
n
INTF.BSY, QSPI_
n
INTF.MMABSY and QSPI_
n
INTF.TENDIF bit set timings.