668-0011 Rabbit Semiconductor, 668-0011 Datasheet - Page 202

• Manufacturer Part Number: 668-0011
• Description: IC MPU RABIT3000A 55.5MHZ128LQFP
• Manufacturer: Rabbit Semiconductor

Specifications of 668-0011

• Rohs Status: RoHS non-compliant
• Processor Type: Rabbit 3000 8-Bit
• Speed: 55.5MHz
• Voltage: 2.5V, 2.7V, 3V, 3.3V
• Mounting Type: Surface Mount
• Package / Case: 128-LQFP
• Features: -
• Other names: 316-1043

23.1.2 I/O Strobes
There are eight I/O strobes available in the Rabbit 3000. Each has a separate 8 KB address
range that can be enabled as a chip select, read strobe, write strobe, or a read/write strobe.
The number of wait states can be set to 1, 3, 7, or 15, and the signal can be active high or
low.
The I/O strobes can be used for devices on the memory bus or the external I/O bus, and can
be enabled to go out on the memory bus alone or both buses. It is also possible to shorten
the read strobe by one clock cycle by pulling in the trailing edge, which guarantees one
clock cycle of hold time for transactions.
192
Register
IB0CR
IB1CR
IB2CR
IB3CR
IB4CR
IB5CR
IB6CR
IB7CR
Figure 23-1. External I/O Bus Cycles
Table 23-1. External I/O Strobes
Port E
PE0
PE1
PE2
PE3
PE4
PE5
PE6
PE7
Pin
I/O Address
A[15:13]
000
001
010
011
100
101
110
111
External I/O Address Range
Rabbit 3000 Microprocessor User’s Manual
0xA000–0xBFFF
0xC000–0xDFFF
0xE000–0xFFFF
0x0000–0x1FFF
0x2000–0x3FFF
0x4000–0x5FFF
0x6000–0x7FFF
0x8000–0x9FFF