EP7312 Datasheet, PDF (10/64 Pages) Cirrus Logic – HIGH-PERFORMANCE, LOW-POWER SYSTEM ON CHIP WITH SDRAM AND ENHANCED DIGITAL AUDIO INTERFACE

EP7312
High-Performance, Low-Power System on Chip
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
Table 14 shows the DC-to-DC Converter Interface pin
assignments.
Table 14. DC-to-DC Converter Interface Pin Assignments
Pin Mnemonic
I/O
Pin Description
DRIVE[1:0]
FB[1:0]
I/O PWM drive output
I
PWM feedback input
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
Table 15 shows the GPIO pin assignments.
Table 15. General Purpose Input/Output 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
Note: Pins are multiplexed. See Table 19 on page 11 for
more information.
Hardware Debug Interface
• Full JTAG boundary scan and Embedded ICE^®
support
Table 16 shows the Hardware Debug Interface pin
assignments.
Table 16. Hardware Debug Interface Pin Assignments
Pin Mnemonic
I/O
Pin Description
TCLK
TDI
TDO
nTRST
TMS
I
JTAG clock
I
JTAG data input
O
JTAG data output
I
JTAG async reset input
I
JTAG mode select
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.
Table 17 shows the LED Flasher pin assignments.
• 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
Table 17. LED Flasher Pin Assignments
Pin Mnemonic
I/O
Pin Description
PD[0]/LEDFLSH
(Note) O LED flasher driver
Note: Pins are multiplexed. See Table 19 on page 11 for
more information.
Internal Boot ROM
The internal 128-byte Boot ROM facilitates download of
saved code to the on-board SRAM/FLASH.
Packaging
The EP7312 is available in a 208-pin LQFP package, 256-
ball PBGA package, or a 204-ball TFBGA package.
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©Copyright Cirrus Logic, Inc. 2003
(All Rights Reserved)
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