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authorSeth Girvan <snth@snthhacks.com>2020-06-09 11:13:39 +0100
committerNick Clifton <nickc@redhat.com>2020-06-09 11:13:39 +0100
commit18ca16bec848a995e3a3a11d43dfa92d0520a3db (patch)
tree553182682bfba69be6f0b7ab80888e82ce0d586b /gas/doc/c-avr.texi
parent6778f1c48531c81fd90b7d2862345b5e2fa99462 (diff)
[PATCH] gas/doc: improve AVR modifiers wording.
* doc/c-avr.texi: Improve wording.
Diffstat (limited to 'gas/doc/c-avr.texi')
-rw-r--r--gas/doc/c-avr.texi37
1 files changed, 23 insertions, 14 deletions
diff --git a/gas/doc/c-avr.texi b/gas/doc/c-avr.texi
index 3e3ffaa0a4..2a1000b271 100644
--- a/gas/doc/c-avr.texi
+++ b/gas/doc/c-avr.texi
@@ -230,12 +230,12 @@ modifier(relocatable-expression)
@item lo8
This modifier allows you to use bits 0 through 7 of
-an address expression as 8 bit relocatable expression.
+an address expression as an 8 bit relocatable expression.
@item hi8
This modifier allows you to use bits 7 through 15 of an address expression
-as 8 bit relocatable expression. This is useful with, for example, the
+as an 8 bit relocatable expression. This is useful with, for example, the
AVR @samp{ldi} instruction and @samp{lo8} modifier.
For example
@@ -248,7 +248,7 @@ ldi r27, hi8(sym+10)
@item hh8
This modifier allows you to use bits 16 through 23 of
-an address expression as 8 bit relocatable expression.
+an address expression as an 8 bit relocatable expression.
Also, can be useful for loading 32 bit constants.
@item hlo8
@@ -258,7 +258,7 @@ Synonym of @samp{hh8}.
@item hhi8
This modifier allows you to use bits 24 through 31 of
-an expression as 8 bit expression. This is useful with, for example, the
+an expression as an 8 bit expression. This is useful with, for example, the
AVR @samp{ldi} instruction and @samp{lo8}, @samp{hi8}, @samp{hlo8},
@samp{hhi8}, modifier.
@@ -275,24 +275,33 @@ ldi r29, hhi8(285774925)
@item pm_lo8
This modifier allows you to use bits 0 through 7 of
-an address expression as 8 bit relocatable expression.
-This modifier useful for addressing data or code from
-Flash/Program memory. The using of @samp{pm_lo8} similar
-to @samp{lo8}.
+an address expression as an 8 bit relocatable expression.
+This modifier is useful for addressing data or code from
+Flash/Program memory by two-byte words. The use of @samp{pm_lo8}
+is similar to @samp{lo8}.
@item pm_hi8
This modifier allows you to use bits 8 through 15 of
-an address expression as 8 bit relocatable expression.
-This modifier useful for addressing data or code from
-Flash/Program memory.
+an address expression as an 8 bit relocatable expression.
+This modifier is useful for addressing data or code from
+Flash/Program memory by two-byte words.
+
+For example, when setting the AVR @samp{Z} register with the @samp{ldi}
+instruction for subsequent use by the @samp{ijmp} instruction:
+
+@smallexample
+ldi r30, pm_lo8(sym)
+ldi r31, pm_hi8(sym)
+ijmp
+@end smallexample
@item pm_hh8
This modifier allows you to use bits 15 through 23 of
-an address expression as 8 bit relocatable expression.
-This modifier useful for addressing data or code from
-Flash/Program memory.
+an address expression as an 8 bit relocatable expression.
+This modifier is useful for addressing data or code from
+Flash/Program memory by two-byte words.
@end table