15 Quad Synchronous Serial Interface (QSPI)
15-36
Seiko Epson Corporation
S1C31D50/D51 TECHNICAL MANUAL
(Rev. 2.00)
Table 15.8.5 Settings of Data Line Drive Length during Dummy Cycle
QSPI_nMMACFG2.DUMDL[3:0] bits
Data line drive length
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
1 clock
These bits must be set to a value smaller than or equal to the QSPI_
n
MMACFG2.DUMLN[3:0] bit
setting.
Bits 11–8 DUMLN[3:0]
These bits set the dummy cycle length in a number of clocks when accessing the external Flash mem-
ory in the memory mapped access mode.
Table 15.8.6 Dummy Cycle Length Settings
QSPI_nMMACFG2.DUMLN[3:0] bits
Dummy cycle length
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
DATTMOD[1:0]
These bits select the transfer mode for the data cycle when accessing the external Flash memory in the
memory mapped access mode.
Table 15.8.7 Transfer Mode for Data, Dummy, and Address Cycles
QSPI_nMMACFG2.DATTMOD[1:0] bits
QSPI_nMMACFG2.DUMTMOD[1:0] bits
QSPI_nMMACFG2.ADRTMOD[1:0] bits
Transfer mode
0x3
Reserved
0x2
Quad transfer mode
The QSDIOn[3:0] pins are used.
0x1
Dual transfer mode
The QSDIOn[1:0] pins are used. The QSDIOn[3:2] pins are not used.
0x0
Single transfer mode
The QSDIOn[1:0] pins are used. The QSDIOn[3:2] pins are not used.