User guide

C M M - 52259 J U N E 1 1 , 2 0 1 0
U S E R G U I D E
8
input, IRQ7* becomes a non-maskable, edge-sensitive input. If this input is used as GPIO the
user application must configure functionality.
LED INDICATORS
The CMM-52259 provides 4 LED indicators; power supply status, reset status, and ethernet
status. The LED indicators provide board status. Figure 1 below shows the different LED
states.
Figure 1: LED Indicators
LED
Color
Function
Default
RESET
Red
MCU in reset state
OFF
+3.3V
Green
+3.3V power present
ON
SPD
Green
Ethernet speed indicator
ON – 100BASE-T operation
OFF – 10BASE-T operation
LINK_ACT
Green
Ethernet link indicator
ON – Ethernet link present
Flash – Link activity
SYSTEM CLOCK
The CMM-52259 provides 2 crystal oscillator inputs to the MCF52259 MCU. A 48MHz crystal
oscillator provides the primary input to the MCU clock module. A secondary, 32.768 kHz crys-
tal oscillator supports internal real-time clock (RTC) functionality. Out of reset, the MCF52259
defaults to its internal 8MHz oscillator setting the System Clock (f
SYS
) to 1.33MHz. The user
must enable and configure the MCU to use the external crystal input. The 32.768 kHz clock
input is dedicated to RTC functionality.
Applications which require USB communications must enable the 48MHz crystal oscillator.
MEMORY
Memory for the CMM-52259 consists of both internal and external FLASH and SRAM memory.
Internal memory consists of 512K bytes FLASH and 64K bytes SRAM memory. External
memory consists of 1Mb SRAM and 64Mb serial FLASH.
Internal FLASH
FLASH memory internal to the MCF52259 consists of 512K bytes of 32-bit memory. It is non-
volatile and bootable. The internal FLASH supports fast page erase and word program opera-
tions. It is divided into 4K byte logical pages that can be erased separately. User application
can locate internal FLASH memory at any 512K boundary within the 4 GB address space. The
value programmed into the FLASHBAR register determines the starting FLASH address. De-
fault register configuration locates internal FLASH memory at address 0x0000_0000.