14
DS508UM1
A simplified block diagram of the EP7312 is shown in Figure 1. All external memory and peripheral de-
vices are connected to the 32-bit data bus using the external 28-bit address bus and control signals.
2.1
CPU Core
The ARM720T consists of an ARM7TDMI 32-bit RISC processor, a unified cache, and a memory man-
agement unit (MMU). The cache is four-way set associative with 8-kbytes organized as 512 lines of
4 words. The cache is directly connected to the ARM7TDMI, and therefore caches the virtual address from
the CPU. When the cache misses, the MMU translates the virtual address into a physical address. A 64-
entry translation lookaside buffer (TLB) is utilized to speed the address translation process and reduce bus
traffic necessary to read the page table. The MMU saves power by only translating the cache misses.
See the ARM720T Data Sheet for a complete description of the various logic blocks that make up the pro-
cessor, as well as all internal register information. The URL (Internet address) for ARM technical manuals
is http://www.arm.com/Documentation/Manuals/.
Figure 1. EP7312 Block Diagram
32.768-KHZ
OSCILLATOR
PLL
INTERRUPT
CONTROLLER
POWER
MANAGEMENT
SDRAM CNTRL
LCD
CONTROLLER
ARM7TDMI
CPU
CORE
8-KBYTE
CACHE
MMU
TIMER
COUNTERS(2)
ARM720T
INTERNAL DATA BUS
3.6864 MHZ
32.768 KHZ
EINT[1-3], FIQ,
MEDCHG
BATOK, EXTPWR
PWRFL, BATCHG
UART2
IrDA
D[0-31]
NPOR, RUN,
RESET, WAKEUP
EXPCLK, WORD, NCS[0-3
EXPRDY, WRITE
MOE, MWE, SDCLK,
SDQM[0:1], SDRAS,
SDCAS
A[0-27],
DRA[0-14]
LCD DRIVE
LED AND
PHOTODIODE
ASYNC
INTERFACE 2
INTERNAL ADDRESS BUS
13-MHZ INPUT
ON-CHIP
BOOT ROM
ASYNC
INTERFACE 1
ON-CHIP SRAM
48 KBYTES
CL-PS6700 INTF
PB[0-1], NCS[4-5]
EXPANSION CNTRL
UART1
EPB BRIDGE
EPB BUS
ICE-JTAG
TEST AND
DEVELOPMENT
WRITE
BUFFER
STATE CONTROL
MEMORY CONTROLLER
LCD DMA
SSI1 (ADC)
PWM
ADCCLK, ADCIN,
ADCOUT, SMPCLK,
ADCCS
SSICLK, SSITXFR,
SSITXDA, SSIRXDA,
SSIRSFR
DC TO DC
PORTS A, B, D (8-BIT)
PORT E (3-BIT)
KEYBD DRIVERS (0-7)
GPIO
RTC
FLASHING LED DRIVE
CODEC
SSI2
DAI
Summary of Contents for EP7312
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Page 58: ...DS508UM1 59 Part II Pin and Register Reference...
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