General Description
The GDC21D601 is the HME’s 32bit high performance microcontroller unit (MCU). The GDC21D601 contains ARM720T, which is a general-purpose 32bit microprocessor, and extensive peripherals: 6 channel 16bit Timer, Watch Dog Timer, 2 channel UART, 2 channel SSPI, 3 channel I2C, Programmable Priority Interrupt Controller, 10 port PIO, 2 channel DMA Controller, External Memory Controller and BUS Controller including chip select logic.
ARM720T is a 32bit Microprocessor with the CPU of the ARM7TDMI, 8KB Cache, enlarged write buffer and Memory Management Unit (MMU). The ARM720T is fully software compatible with the ARM processor family.

The general descriptions of the GDC21D601 like following :
• On-Chip Modular Architecture (using AMBA)
• Utilizes the ARM720T(“ARM7TDMI with 8Kbyte Cache and MMU”) 32bit RISC Family
• 8Kbyte internal SRAM
• support 8bit/16bit/32bit external Data bus width
• Eight Programmable Chip Select Outputs with EXPRDY
• Support Little and Big Endian memory format
• Low Power Consumption using Power Management Unit
• Fully static operation : Max. 80MHz
• Two 32bit DMA Controllers (External request only)
• Programmable Priority Interrupt Controller (6 external sources)
• Two DRAM Banks Support
• Six 16bit Multi Function Timers / Counters for General Purpose Applications
• One 8bit Watch Dog Timer (WDT)
• Real Time Clock : 32.768 KHz
• Three UARTs (Universal Asynchronous Receiver Transmitter) compatible with 16C550 UART, one UART with Smart card interface
• Two SSPIs (Synchronous Serial Peripheral Interface) with FIFO
• Three I2C Master/Slave Controllers
• Programmable Input/Output (8bit 10 channel)
• 208 MQFP Package