GMS90 Series
GMS90C54/56/58, 97C54/56/58
GMS90L54/56/58, 97L54/56/58 (Low voltage versions)
• Fully compatible to standard MCS-51 microcontroller
• Wide operating frequency up to 40MHz (for more detail, see “GMS90 Series Selection Guide”)
• 16K/24K/32K bytes (EP)ROM
• 256 × 8 RAM
• 64K external program memory space
• 64K external data memory space
• Four 8-bit ports
• Three 16-bit Timers / Counters (Timer2 with up/down counter feature)
• USART
• One clock output port
• Programmable ALE pin enable / disable
• Six interrupt sources, two priority levels
• Power saving Idle and power down mode
• Quick pulse programming algorithm (in the OTP devices)
• 2-level program memory lock (in the OTP devices)
• 2.7Volt low voltage version available
• P-DIP-40, P-LCC-44, P-MQFP-44 package
Block Diagram
RAM
I/O
PORT 0
256 × 8
T 0
T 1
I/O
I/O
PORT 1
PORT 2
8-BIT
USART
CPU
T 2
ROM / EPROM
GMS9XX54: 16K × 8
GMS9XX56: 24K × 8
GMS9XX58: 32K × 8
I/O
PORT 3
Dec. 1998 Ver 3.0
3