Functional Description

7.3.2.25BDM

Entering halt mode via the BDM port (by asserting the external BKPT pin) will cause the CPU to exit any low-power mode.

7.3.2.26JTAG

The JTAG (Joint Test Action Group) controller logic is clocked using the TCLK input and is not affected by the system clock. The JTAG cannot generate an event to cause the CPU to exit any low-power mode. Toggling TCLK during any low-power mode will increase the system current consumption.

7.3.3Summary of Peripheral State During Low-Power Modes

The functionality of each of the peripherals and CPU during the various low-power modes is summarized in Table 7-7.The status of each peripheral during a given mode refers to the condition the peripheral automatically assumes when the STOP instruction is executed and the LPCR[LPMD] field is set for the particular low-power mode. Individual peripherals may be disabled by programming its dedicated control bits. The wakeup capability field refers to the ability of an interrupt or reset by that peripheral to force the CPU into run mode.

Table 7-7. CPU and Peripherals in Low-Power Modes

 

Module

 

Peripheral Status 1 / Wakeup Capability

 

 

 

Wait Mode

Doze Mode

Stop Mode

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CPU

Stopped

No

Stopped

No

Stopped

No

 

 

 

 

 

 

 

 

 

 

 

SRAM

Stopped

No

Stopped

No

Stopped

No

 

 

 

 

 

 

 

 

 

 

 

Flash

Stopped

No

Stopped

No

Stopped

No

 

 

 

 

 

 

 

 

 

 

 

System Integration Module

Enabled

Yes 3

Enabled

Yes 3

Stopped

No

 

 

SDRAM Controller

Enabled

No

Enabled

No

Stopped

No

 

 

 

 

 

 

 

 

 

 

 

Chip Select Module

Enabled

No

Enabled

No

Stopped

No

 

 

 

 

 

 

 

 

 

 

 

DMA Controller

Enabled

Yes

Enabled

Yes

Stopped

No

 

 

 

 

 

 

 

 

 

 

 

UART0, UART1 and UART2

Enabled

Yes2

Enabled

Yes2

Stopped

No

 

 

I2C Module

Enabled

Yes2

Enabled

Yes2

Stopped

No

 

 

QSPI

Enabled

Yes2

Enabled

Yes2

Stopped

No

 

 

DMA Timers

Enabled

Yes2

Enabled

Yes2

Stopped

No

 

 

Interrupt controller

Enabled

Yes 2

Enabled

Yes2

Enabled

Yes2

 

 

Fast Ethernet Controller

Enabled

Yes2

Enabled

Yes2

Stopped

No

 

 

I/O Ports

Enabled

No

Enabled

No

Enabled

No

 

 

 

 

 

 

 

 

 

 

 

Reset Controller

Enabled

Yes 3

Enabled

Yes3

Enabled

Yes3

 

 

 

 

 

 

 

 

 

 

7-16

MCF5282 User’s Manual

MOTOROLA

Page 184
Image 184
Motorola MCF5282, MCF5281 user manual Summary of Peripheral State During Low-Power Modes, 2.25 BDM, Jtag