10 Copyright 2010 Cirrus Logic (All Rights Reserved) DS667F2
EP9307
ARM9 SOC with Ethernet, USB, Display and Touchscreen
Real-Time Clock with Software Trim
The software trim feature on the real time clock (RTC)
provides software controlled digital compensation of the
32.768 KHz input clock. This compensation is accurate to
±1.24 sec/month.
Note: A real time clock must be connected to RTCXTALI or
the EP9307 device will not boot.
PLL and Clocking
The Processor and the Peripheral Clocks operate from a
single 14.7456 MHz crystal.
The Real Time Clock operates from a 32.768 KHz
external oscillator.
Timers
The Watchdog Timer ensures proper operation by
requiring periodic attention to prevent a reset-on-time-
out.
Two 16-bit timers operate as free running down-counters
or as periodic timers for fixed interval interrupts and have
a range of 0.03 ms to 4.27 seconds.
One 32-bit timer, plus a 6-bit prescale counter, has a
range of 0.03 μs to 73.3 hours.
One 40-bit debug timer, plus a 6-bit prescale counter, has
a range of 1.0 μs to 12.7 days.
Interrupt Controller
The interrupt controller allows up to 62 interrupts to
generate an Interrupt Request (IRQ) or Fast Interrupt
Request (FIQ) signal to the processor core. Thirty-two
hardware priority assignments are provided for assisting
IRQ vectoring, and two levels are provided for FIQ
vectoring. This allows time critical interrupts to be
processed in the shortest time possible. Internal
interrupts may be programmed as active high or active
low level sensitive inputs. GPIO pins programmed as
interrupts may be programmed as active high level
sensitive, active low level sensitive, rising edge triggered,
falling edge triggered, or combined rising/falling edge
triggered.
• Supports 64 interrupts from a variety of sources (such
as UARTs, GPIO, and key matrix)
• Routes interrupt sources to either the ARM920T’s
IRQ or FIQ (Fast IRQ) inputs
• Three dedicated off-chip interrupt lines operate as
active high level sensitive interrupts
• Any of the 16 GPIO lines maybe configured to
generate interrupts
• Software supported priority mask for all FIQs and
IRQs
Dual LED Drivers
Two pins are assigned specifically to drive external
LEDs.
General Purpose Input/Output (GPIO)
The 14 EGPIO pins may each be configured individually
as an output, an input, or an interrupt input.
There are 22 pins that may alternatively be used as input,
output, or open-drain pins, but do not support interrupts.
These pins are:
• Key Matrix ROW[7:0], COL[7:0]
• Ethernet MDIO
• Both LED Outputs
• Two-wire Clock and Data
• GGPIO[2]
• HGPIO[7:2]
6 pins may alternatively be used as inputs only:
• CTSn, DSRn/DCDn
• 4 Interrupt Lines
2 pins may alternatively be used as outputs only:
•RTSn
•ARSTn
Table K. Real-Time Clock with Pin Assignments
Pin Mnemonic Pin Name - Description
RTCXTALI Real-Time Clock Oscillator Input
RTCXTALO Real-Time Clock Oscillator Output
Table L. PLL and Clocking Pin Assignments
Pin Mnemonic Pin Name - Description
XTALI Main Oscillator Input
XTALO Main Oscillator Output
VDD_PLL Main Oscillator Power
GND_PLL Main Oscillator Ground
Table M. External Interrupt Controller Pin Assignment
Pin Mnemonic Pin Name - Description
INT[2:0] External Interrupts 2, 1, 0
Table N. Dual LED Pin Assignments
Pin Mnemonic
Pin Name -
Description
Alternative Usage
GRLED Green LED General Purpose I/O
REDLED Red LED General Purpose I/O
