Motorola MCF5281, MCF5282 user manual Qspi Delay Register Qdlyr, Qspics Qmrcpol =, Qcd

Models: MCF5282 MCF5281

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Programming Model

 

 

 

Table 22-4. QMR Field Descriptions (continued)

 

 

 

 

Bits

Name

 

Description

 

 

 

8

CPHA

Clock phase. Defines the QSPI_CLK clock-phase.

 

 

0

Data captured on the leading edge of QSPI_CLK and changed on the following edge of QSPI_CLK.

 

 

1

Data changed on the leading edge of QSPI_CLK and captured on the following edge of QSPI_CLK.

 

 

 

7–0

BAUD

Baud rate divider. The baud rate is selected by writing a value in the range 2–255. A value of zero disables

 

 

the QSPI. A value of 1 is an invalid setting. The desired QSPI_CLK baud rate is related to the system clock

 

 

and QMR[BAUD] by the following expression:

 

 

 

QMR[BAUD] = fSYS / [2 ⋅ (desired QSPI_CLK baud rate)]

Figure 22-4shows an example of a QSPI clocking and data transfer.

QSPI_CLK

QSPI_Dout

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

 

 

 

msb

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

QSPI_Din

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

A

B

 

QSPI_CS

QMR[CPOL] = 0

Chip selects are active low

QMR[CPHA] = 1

A = QDLYR[QCD]

QCR[CONT] = 0

B = QDLYR[DTL]

Figure 22-4. QSPI Clocking and Data Transfer Example

22.5.2 QSPI Delay Register (QDLYR)

Figure 22-5shows the QDLYR.

15

14

8

7

0

Field SPE

Reset

R/W

Address

QCD

DTL

 

 

0000_0100_0000_0100

R/W

IPSBAR + 0x344

Figure 22-5. QSPI Delay Register (QDLYR)

MOTOROLA

Chapter 22. Queued Serial Peripheral Interface (QSPI) Module

22-11

Page 467
Image 467
Motorola MCF5281, MCF5282 Qspi Delay Register Qdlyr, Qspics Qmrcpol =, Qmrcpha = = Qdlyrqcd Qcrcont = = Qdlyrdtl, Qcd