20-668-0011 Rabbit Semiconductor, 20-668-0011 Datasheet - Page 286

• Manufacturer Part Number: 20-668-0011
• Description: IC MPU RABIT3000A 55.5MHZ128LQFP
• Manufacturer: Rabbit Semiconductor

Specifications of 20-668-0011

• 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
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 55.5 MHz
• Operating Supply Voltage: 1.8 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 55 C
• Number Of Programmable I/os: 56
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 316-1061

B.1.6 Stack Protection
Stack overflow and underflow can now be detected. Low and high stack limits can be set
on 256-byte boundaries. When a stack-relative memory access occurs within 16 bytes of
these limits (or outside of them), a new Priority 3 stack violation interrupt occurs. The 16-
byte buffer exists to allow stack protection even if the stack is placed against a memory
segment boundary.
Figure B-2 shows one possible stack layout. A 2048-byte stack is set up by setting
STKHLR to 0x00E0, STKLLR to 0x00D8, and SP to 0xDFF0. Any stack-relative mem-
ory accesses above 0xDFEF (i.e., stack underflow) or below 0xD810 (i.e., overflow)
would trigger the stack violation interrupt.
276
TKHLR = 0x00E0
TKLLR = 0x00D8
0xDFEF
0xDFF0
0xD80F
0xD810
0xD800
0xE000
Figure B-2. Simple Stack Protection Layout
Rabbit 3000 Microprocessor User’s Manual
Stack access in this
region triggers an
interrupt
Stack access in this
region is allowed
Stack access in this
region triggers an
interrupt