make stack frame for procedure parameters
Create the stack frame required by most block-structured high-level languages. The imm16 operand specifies the number of bytes of dynamic storage allocated on the stack for the routine being entered. The imm8 operand specifies the lexical nesting level (0 to 31) of the routine within the high-level language source code. The nesting level determines the number of stack frame pointers copied into the new stack frame from the preceding frame.
Create a stack frame with 0xfecd bytes of dynamic storage on the stack and a nesting level of 0xff.
enter $0xfecd, $0xff