GEMINI
MCUK991001G8
Section 7
Issue 1
Technical Guide
– 27 –
Revision 0
7 GEMINI
7.1 Introduction
Gemini contains the DSP, CPU and GSM timing functions and many peripheral functions. The software for the DSP is
contained in masked ROM.
7.2 Functional Description
Figure 7.1: GEMINI Block Diagram
7.2.1 Digital Signal Processor
The Digital Signal Processor (DSP) core is compatible with the Texas Instruments TMS350C5xx family of DSPs. Included in
the DSP core is an interface to the CPU by a shared memory interface.
The DSP memory is also located within GEMINI. The ROM code size is determined by the size of the software.
7.2.2 CPU
The CPU is an ARM7 32 bit RISC micro-controller core. It can work in 32 or 16-bit instruction modes and on 32, 16 or 8-bit
data. Pipelining is employed so that all parts of the processing and memory system can operate continuously.
CPU clock speed is selectable and is set to achieve optimum speed for memory access.
For 120 ns access FLASH and RAM a 13 MHz clock gives 1 wait state access to both devices.
Memory Access Times
Clock Speed
Memory Access Time
Additional Access time per wait state
19.5 MHz
41 ns
51 ns
13 MHz
67 ns
77 ns
9.75 MHz
91 ns
102 ns
6.5 MHz
144 ns
154 ns
4.875 MHz
194 ns
204 ns
3.75 MHz
298 ns
308 ns
GSM
TDMA
TIMER
TPU
DSP
CORE
SIM
I/F
JTAG
DSP ROM
DSP RAM
IRQ
MEM
I/F
SERIAL I/F
I/O
PWM
UART
ARM
INTERFACE
TIMERS
SPEECH
INTERFACE
BASEBAND
INTERFACE
10087-1
