Synchronous serial interface, Lcd controller, Interrupt controller – Cirrus Logic EP7309 User Manual
Page 8: Real-time clock, Keypad interface
8
Copyright Cirrus Logic, Inc. 2011
(All Rights Reserved)
DS507F2
EP7309
High-Performance, Low-Power System on Chip
Synchronous Serial Interface
•
ADC (SSI) Interface: Master mode only; SPI and
Microwire1-compatible (128 kbps operation)
•
Selectable serial clock polarity
LCD Controller
A DMA address generator is provided that fetches video
display data for the LCD controller from memory. The display
frame buffer start address is programmable, allowing the LCD
frame buffer to be in SDRAM, internal SRAM or external
SRAM.
•
Interfaces directly to a single-scan panel monochrome STN
LCD
•
Interfaces to a single-scan panel color STN LCD with
minimal external glue logic
•
Panel width size is programmable from 32 to 1024 pixels in
16-pixel increments
•
Video frame buffer size programmable up to
128 KB
•
Bits per pixel of 1, 2, or 4 bits
64-Keypad Interface
Matrix keyboards and keypads can be easily read by the
EP7309. A dedicated 8-bit column driver output generates
strobes for each keyboard column signal. The pins of Port A,
when configured as inputs, can be selectively OR'ed together
to provide a keyboard interrupt that is capable of waking the
system from a STANDBY or IDLE state.
•
Column outputs can be individually set high with the
remaining bits left at high-impedance
•
Column outputs can be driven all-low, all-high, or all-high-
impedance
•
Keyboard interrupt driven by OR'ing together all Port A
bits
•
Keyboard interrupt can be used to wake up the system
•
8
8 keyboard matrix usable with no external logic, extra
keys can be added with minimal glue logic
Interrupt Controller
When unexpected events arise during the execution of a
program (i.e., interrupt or memory fault) an exception is
usually generated. When these exceptions occur at the same
time, a fixed priority system determines the order in which
they are handled. The EP7309 interrupt controller has two
interrupt types: interrupt request (IRQ) and fast interrupt
request (FIQ). The interrupt controller has the ability to control
interrupts from 22 different FIQ and IRQ sources.
•
Supports 22 interrupts from a variety of sources (such as
UARTs, SSI1, and key matrix.)
•
Routes interrupt sources to the ARM720T’s IRQ or FIQ
(Fast IRQ) inputs
•
Five dedicated off-chip interrupt lines operate as level
sensitive interrupts
.
Note:
Pins are multiplexed. See
for
more information.
Real-Time Clock
The EP7309 contains a 32-bit Real Time Clock (RTC) that can
be written to and read from in the same manner as the timer
counters. It also contains a 32-bit output match register which
can be programmed to generate an interrupt.
•
Driven byan external 32.768 kHz crystal oscillator
Pin Mnemonic
I/O
Pin Description
ADCLK
O
SSI1 ADC serial clock
ADCIN
I
SSI1 ADC serial input
ADCOUT
O
SSI1 ADC serial output
nADCCS
O
SSI1 ADC chip select
SMPCLK
O
SSI1 ADC sample clock
Table 7. Serial Interface Pin Assignments
Pin Mnemonic
I/O
Pin Description
CL1
O
LCD line clock
CL2
O
LCD pixel clock out
DD[3:0]
O
LCD serial display data bus
FRM
O
LCD frame synchronization pulse
M
O
LCD AC bias drive
Table 8. LCD Interface Pin Assignments
Pin Mnemonic
I/O
Pin Description
COL[7:0]
O
Keyboard scanner column
drive
Table 9. Keypad Interface Pin Assignments
Pin Mnemonic
I/O
Pin Description
nEINT[2:1]
I
External interrupt
EINT[3]
I
External interrupt
nEXTFIQ
I
External Fast Interrupt input
nMEDCHG/nBROM
(Note)
I
Media change interrupt input
Table 10. Interrupt Controller Pin Assignments