15 Quad Synchronous Serial Interface (QSPI)
15-32
Seiko Epson Corporation
S1C31D50/D51 TECHNICAL MANUAL
(Rev. 2.00)
QSPI Ch.
n
Transmit Data Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
QSPI_nTXD
15–0 TXD[15:0]
0x0000
H0
R/W –
Bits 15–0 TXD[15:0]
Data can be written to the transmit data buffer through these bits. Writing to these bits starts data
transfer. Transmit data can be written when the QSPI_
n
INTF.TBEIF bit = 1 regardless of whether data
is being output from the QSDIO
n
pins or not.
Note that the upper data bits that exceed the data bit length configured by the QSPI_
n
MOD.
CHLN[3:0] bits will not be output from the QSDIO
n
pin.
Note: Be sure to avoid writing to the QSPI_nTXD register when the QSPI_nINTF.TBEIF bit = 0. Other-
wise, transfer data cannot be guaranteed.
QSPI Ch.
n
Receive Data Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
QSPI_nRXD
15–0 RXD[15:0]
0x0000
H0
R
–
Bits 15–0 RXD[15:0]
The receive data buffer can be read through these bits. Received data can be read when the QSPI_
n
INTF.RBFIF bit = 1 regardless of whether data is being input from the QSDIO
n
pin or not.
Note that the upper bits that exceed the data bit length configured by the QSPI_
n
MOD.CHLN[3:0]
bits become 0.
QSPI Ch.
n
Interrupt Flag Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
QSPI_nINTF
15–8 –
0x00
–
R
–
7
BSY
0
H0
R
6
MMABSY
0
H0
R
5–4 –
0x0
–
R
3
OEIF
0
H0/S0
R/W Cleared by writing 1.
2
TENDIF
0
H0/S0
R/W
1
RBFIF
0
H0/S0
R
Cleared by reading the
QSPI_nRXD register.
0
TBEIF
1
H0/S0
R
Cleared by writing to the
QSPI_nTXD register.
Bits 15–8 Reserved
Bit 7
BSY
This bit indicates the QSPI operating status.
1 (R):
Transmit/receive busy
0 (R):
Idle
Bit 6
MMABSY
This bit indicates the QSPI memory mapped access operating status.
1 (R):
Memory mapped access state machine busy
0 (R):
Idle
Bits 5–4
Reserved