mcf5272 Freescale Semiconductor, Inc, mcf5272 Datasheet - Page 340

• Manufacturer Part Number: mcf5272
• Description: Mcf5272 Coldfire Integrated Microprocessor User
• Manufacturer: Freescale Semiconductor, Inc

Module Description
14.3.1 Interface and Pins
The module provides as many as 15 ports and a total of seven signals: QSPI_Dout,
QSPI_Din, QSPI_CLK, QSPI_CS0, QSPI_CS1, QSPI_CS2, and QSPI_CS3.
Peripheral chip-select signals, QSPI_CS[0:3], are used to select an external device as the
source or destination for serial data transfer. Signals are asserted at a logic level
corresponding to the value of the QSPI_CS[3:0] bits in the command RAM whenever a
command in the queue is executed. More than one chip-select signal can be asserted
simultaneously.
Although QSPI_CS[0:3] will function as simple chip selects in most applications, up to 15
ports can be selected by decoding them with an external 4-to-16 decoder.
Note that chip selects QSPI_CS[3:1] are multiplexed with other pin functions. QSPI_Dout,
QSPI_CLK, and QSPI_CS0 are multiplexed with MCF5272 configuration inputs that only
function during system reset.
14-2
Internal Bus
Queue Control
Control Logic
Comparator
End Queue
Counter
Pointer
Pointer
Control
Queue
Status
Block
Delay
Regs
Regs
CLKIN
Figure 14-1. QSPI Block Diagram
Divide by 2
Register
Address
Done
4
QSPI
Logic
Array
4
MCF5272 User’s Manual
Select
Command
Chip
4
4
Baud Rate
Generator
80-Byte
QSPI
RAM
MSBit
8/16 Bit Shift Reg.
Rx/Tx Data Reg.
LSBit
4
Register
QSPI
Data
QSPI_Din
QSPI_Dout
QSPI_CS[3:0]
QSPI_CLK
MOTOROLA