From: sater <none@none>
Date: Thu, 12 Jul 1984 15:16:23 +0000 (+0000)
Subject: Initial revision
X-Git-Tag: release-5-5~6201
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=a81a1917f5545024f78485ea6dd84932205a6f65;p=ack.git

Initial revision
---

diff --git a/man/6809_as.1 b/man/6809_as.1
new file mode 100644
index 000000000..7ac2ede81
--- /dev/null
+++ b/man/6809_as.1
@@ -0,0 +1,147 @@
+.\" $Header$
+.TH 6809_AS 1
+.ad
+.SH NAME
+6809_as \- assembler for 6809
+.SH SYNOPSIS
+/usr/em/lib/6809_as [options] argument ...
+.SH DESCRIPTION
+This assembler is made with the general framework
+described in \fIuni_ass\fP(6).
+.SH SYNTAX
+.IP registers
+The 6809 contains four 8-bit registers registers:
+two accumulators (a and b),
+a direct page register (dp),
+and a condition code register (cc),
+and five 16-bit registers:
+two index registers (x and y),
+a user an a hardware stack pointer (u resp. s),
+and a program counter (pc).
+The index registers and the stack pointers are indexable.
+Accumulators a and b can be concatenated to form
+the double accumulator d,
+of which a is the high and b is the low byte.
+An instruction that refers to accumulator a
+has an "a" as last character.
+In the same way a "b" means that the instruction
+uses b as accumulator.
+.IP "pseudo instructions"
+The 6809 assembler recognizes one additional instruction
+that is not translated into a machine instruction: setdp.
+It expects an expression as argument.
+This is used for efficient address encoding of some addressing
+mode (see below).
+.IP "addressing modes"
+.nf
+.ta 8 16 24 32 40 48
+syntax		meaning (name)
+
+reg		The operand of the instruction is in `reg'.
+
+reglist		`reglist' is a either list of registers, seperated
+		by ','s, or the word "all". It encodes in a register
+		save mask, where "all" means all registers, that can
+		be used by the push-pull instructions pshs, pshu,
+		puls, and pulu.
+
+<expr		The one-byte value of `expr' is an address within
+		a 256-byte page. The particular page in use is
+		indicated by the contents of dp, so `expr' is the
+		low byte of the effective address of the operand,
+		and dp the high byte. (direct)
+
+>expr		The two-byte value of `expr' is the exact memory
+		address. Not that this mode always requires one
+		byte more than "<expr". (extended)
+
+expr		The value of `expr' is an address.
+		Except for long branches, this value is examined
+		first to see if a short encoding is possible.
+		When the instruction is a short branch, the value
+		is checked to see if the address is not too remote,
+		because in that case this branch is automatically
+		replaced by a long branch. When the instruction is
+		not a branch, the high byte of the value is compared
+		with the value of the argument of the last setdp
+		pseudo.  If they are equal, this mode is replaced by
+		"<expr", else by ">expr".
+		(relative for branch-instructions)
+
+#expr		The value of `expr' is one- or two-byte immediate
+		data. (immediate)
+
+(expr)		The value of `expr' is a pointer to the address
+		of the operand. (indirect)
+
+expr, reg	The value of `expr' added to the contents of `reg'
+		(which must be a 16-bit register) yields the
+		effective address of the operand.
+		(constant-offset indexed)
+
+, ireg		The contents of `ireg' (which must be indexable)
+		yields the effective address of the operand.
+		(constant-offset indexed)
+
+(expr, reg)	The value of `expr' added to the contents of `reg'
+		(which must be a 16-bit register) yields a pointer
+		to the effective address of the operand.
+		(constant-offset indexed indirect)
+
+(, ireg)	The contents of `ireg' (which must be indexable)
+		yields a pointer to the effective address of the
+		operand. (constant-offset indexed indirect)
+
+ac, ireg	The contents of `ac' (which must be an accumulator)
+		added to the contents of `ireg' (which must be
+		indexable) yields the effective address of the
+		operand. (accumulator indexed)
+
+(ac, ireg)	The contents of `ac' (which must be an accumulator)
+		added to the contents of `ireg' (which must be
+		indexable) yields a pointer to the effective address
+		of the operand. (accumulator indexed indirect)
+
+,ireg+
+,ireg++		The contents of `ireg' (which must be indexable) is
+		used as effective address of the operand. After that
+		it is incremented by 1 (+) or 2 (++).
+		(auto-increment)
+
+(,ireg++)	The contents of `ireg' (which must be indexable) is
+		used as a pointer to the effective address of the
+		operand. After that it is incremented by 2.
+		(auto-increment indirect)
+
+,-ireg
+,--ireg		`ireg' (which must be indexable) is decremented
+		by 1 (-) or 2 (--). After that, its contents is used
+		as effective address of the operand.
+		(auto-decrement)
+
+(,--ireg)	`ireg (which must be indexable) is decremented by 2.
+		After that, its contents is used as a pointer to the
+		effective address of the operand.
+		(auto-decrement indirect)
+
+.fi
+.SH "SEE ALSO"
+uni_ass(6),
+ack(1),
+.br
+MC6809 preliminary programming manual, Motorola Inc., First Edition, 1979
+.SH EXAMPLE
+An example of 6809 assembly code.
+.nf
+.ta 8 16 24 32 40 48
+	contby = 80
+
+	compgo:	lda	#contby
+		ldx	#table - 2	!start of table
+
+		clrb
+	co1:	addb	#2
+		lsra
+		bcc	co1
+		jmp	(b, x)		!accumulator offset indirect
+.fi