15 Quad Synchronous Serial Interface (QSPI)
15-30
Seiko Epson Corporation
S1C31D50/D51 TECHNICAL MANUAL
(Rev. 2.00)
Table 15.8.2 Setting of Number of Data Transfer Clocks
QSPI_nMOD.CHLN[3:0] bits
Number of data transfer clocks
0xf
16 clocks
0xe
15 clocks
0xd
14 clocks
0xc
13 clocks
0xb
12 clocks
0xa
11 clocks
0x9
10 clocks
0x8
9 clocks
0x7
8 clocks
0x6
7 clocks
0x5
6 clocks
0x4
5 clocks
0x3
4 clocks
0x2
3 clocks
0x1
2 clocks
0x0
Setting prohibited
Bits 7–6
TMOD[1:0]
These bits select a transfer mode.
Table 15.8.3 Transfer Mode
QSPI_nMOD.
TMOD[1:0] bits
Transfer mode
0x3
Reserved
0x2
Quad transfer mode
The QSDIOn[3:0] pins are configured as input or out-
put pins according to the QSPI_nMOD.DIR bit setting.
0x1
Dual transfer mode
The QSDIOn[1:0] pins are configured as input or out-
put pins according to the QSPI_nMOD.DIR bit setting.
The QSDIOn[3:2] pins are not used.
0x0
Single transfer mode
The QSDIOn0 and QSDIOn1 pins are configured as an
output pin and an input pin, respectively.
The QSDIOn[3:2] pins are not used.
Bit 5
PUEN
This bit enables pull-up/down of the pins that are configured as an input or are not used.
1 (R/W): Enable pull-up/down
0 (R/W): Disable pull-up/down
For more information, refer to “Input Pin Pull-Up/Pull-Down Function.”
Bit 4
NOCLKDIV
This bit selects QSPICLK
n
in master mode. This setting is ineffective in slave mode.
1 (R/W): QSPICLK
n
frequency = CLK_QSPI
n
frequency ( = 16-bit timer operating clock frequency)
0 (R/W): QSPICLK
n
frequency = 16-bit timer output frequency / 2
For more information, refer to “QSPI Operating Clock.”
Bit 3
LSBFST
This bit configures the data format (input/output permutation).
1 (R/W): LSB first
0 (R/W): MSB first
Bit 2
CPHA
Bit 1
CPOL
These bits set the QSPI clock phase and polarity. For more information, refer to “QSPI Clock (QSPI-
CLK
n
) Phase and Polarity.”