Pll and clocking, Dc-to-dc converter interface (pwm), Timers – Cirrus Logic EP7309 User Manual
Page 9: General purpose input/output (gpio), Hardware debug interface, Led flasher
DS507F2
Copyright Cirrus Logic, Inc. 2011
(All Rights Reserved)
9
EP7309
High-Performance, Low-Power System on Chip
PLL and Clocking
•
Processor and Peripheral Clocks operate from a single
3.6864 MHz crystal or external 13 MHz clock
•
Programmable clock speeds allow the peripheral bus to run
at 18 MHz when the processor is set to 18 MHz and at
36 MHz when the processor is set to 36, 49 or 74 MHz
DC-to-DC converter interface (PWM)
•
Provides two 96 kHz clock outputs with programmable
duty ratio (from 1-in-16 to 15-in-16) that can be used to
drive a positive or negative DC to DC converter
Timers
•
Internal (RTC) timer
•
Two internal 16-bit programmable hardware count-down
timers
General Purpose Input/Output (GPIO)
•
Three 8-bit and one 3-bit GPIO ports
•
Supports scanning keyboard matrix
Note:
Pins are multiplexed. See
for
more information.
Hardware debug Interface
•
Full JTAG boundary scan and Embedded ICE
support
LED Flasher
A dedicated LED flasher module can be used to generate a low
frequency signal on Port D pin 0 for the purpose of blinking an
LED without CPU intervention. The LED flasher feature is
ideal as a visual annunciator in battery powered applications,
such as a voice mail indicator on a portable phone or an
appointment reminder on a PDA.
•
Software adjustable flash period and duty cycle
•
Operates from 32 kHz RTC clock
•
Will continue to flash in IDLE and STANDBY states
•
4 mA drive current
Note:
Pins are multiplexed. See
for
more information.
Pin Mnemonic
Pin Description
RTCIN
Real-Time Clock Oscillator Input
RTCOUT
Real-Time Clock Oscillator Output
VDDRTC
Real-Time Clock Oscillator Power
VSSRTC
Real-Time Clock Oscillator Ground
Table 11. Real-Time Clock Pin Assignments
Pin Mnemonic
Pin Description
MOSCIN
Main Oscillator Input
MOSCOUT
Main Oscillator Output
VDDOSC
Main Oscillator Power
VSSOSC
Main Oscillator Ground
Table 12. PLL and Clocking Pin Assignments
Pin Mnemonic
I/O
Pin Description
DRIVE[1:0]
I/O
PWM drive output
FB[1:0]
I
PWM feedback input
Table 13. DC-to-DC Converter Interface Pin Assignments
Pin Mnemonic
I/O
Pin Description
PA[7:0]
I/O
GPIO port A
PB[7:0]
I/O
GPIO port B
PD[0]/LEDFLSH
(Note)
I/O
GPIO port D
PD[5:1]
I/O
GPIO port D
PD[7:6]/SDQM[1:0]
(Note)
I/O
GPIO port D
PE[1:0]/BOOTSEL[1:0] (Note)
I/O
GPIO port E
PE[2]/CLKSEL
(Note)
I/O
GPIO port E
Table 14. General Purpose Input/Output Pin Assignments
Pin Mnemonic
I/O
Pin Description
TCLK
I
JTAG clock
TDI
I
JTAG data input
TDO
O
JTAG data output
nTRST
I
JTAG async reset input
TMS
I
JTAG mode select
Table 15. Hardware Debug Interface Pin Assignments
Pin Mnemonic
I/O
Pin Description
PD[0]/LEDFLSH
(Note)
O
LED flasher driver
Table 16. LED Flasher Pin Assignments