Motorola ColdFire MCF5281 - Manual (Page 412)

Queued Serial Peripheral Interface (QSPI)
22-8 Freescale Semiconductor
22.3.6 QSPI Data Register (QDR)
The QDR is used to access QSPI RAM indirectly. The CPU reads and writes all data from and to the QSPI
RAM through this register.
A write to QDR causes data to be written to the RAM entry specified by QAR[ADDR]. This also causes
the value in QAR to increment. Correspondingly, a read at QDR returns the data in the RAM at the address
specified by QAR[ADDR]. This also causes QAR to increment. A read access requires a single wait state.
22.3.7 Command RAM Registers (QCR0–QCR15)
The command RAM is accessed using the upper byte of the QDR; the QSPI cannot modify information in
command RAM. There are 16 bytes in the command RAM. Each byte is divided into two fields. The chip
select field enables external peripherals for transfer. The command field provides transfer operations.
IPSBAR
Offset:
0x00_0350 (QAR) Access: User read/write
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
R 0 0 0 0 0 0 0 0 0 0
ADDR
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Figure 22-7. QSPI Address Register (QAR)
Table 22-7. QAR Field Descriptions
Field Description
15–6 Reserved, must be cleared.
5–0
ADDR
Address used to read/write the QSPI RAM. Ranges are as follows:
0x00–0x0F Transmit RAM
0x10–0x1F Receive RAM
0x20–0x2F Command RAM
0x30–0x3F Reserved
IPSBAR
Offset:
0x00_0354 (QDR) Access: User read/write
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
R
DATA
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Figure 22-8. QSPI Data Register (QDR)
Table 22-8. QDR Field Descriptions
Field Description
15–0
DATA
A write to this field causes data to be written to the QSPI RAM entry specified by QAR[ADDR]. Similarly, a read of
this field returns the data in the QSPI RAM at the address specified by QAR[ADDR]. During command RAM
accesses (QAR[ADDR] = 0x20–0x2F), only the most significant byte of this field is used.
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3