From 9e80202352dd49bdd9e67b8b906d86f058431505 Mon Sep 17 00:00:00 2001
From: Timothy Pearson <tpearson@raptorengineering.com>
Date: Sat, 11 May 2019 15:12:49 -0500
Subject: Initial import of abandoned HQEMU version 2.5.2

---
 src/roms/SLOF/board-js2x/slof/freq.fs | 39 +++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 src/roms/SLOF/board-js2x/slof/freq.fs

(limited to 'src/roms/SLOF/board-js2x/slof/freq.fs')

diff --git a/src/roms/SLOF/board-js2x/slof/freq.fs b/src/roms/SLOF/board-js2x/slof/freq.fs
new file mode 100644
index 0000000..9f1d36d
--- /dev/null
+++ b/src/roms/SLOF/board-js2x/slof/freq.fs
@@ -0,0 +1,39 @@
+\ *****************************************************************************
+\ * Copyright (c) 2004, 2008 IBM Corporation
+\ * All rights reserved.
+\ * This program and the accompanying materials
+\ * are made available under the terms of the BSD License
+\ * which accompanies this distribution, and is available at
+\ * http://www.opensource.org/licenses/bsd-license.php
+\ *
+\ * Contributors:
+\ *     IBM Corporation - initial implementation
+\ ****************************************************************************/
+
+
+\ Use the HPET to calculate various frequencies.
+
+\ Make HPET run.
+1 10 hpet!
+
+\ Set PMC1 to count CPU cycles.
+f00 mmcr0!
+
+d# 1000000000000000 4 hpet@ / CONSTANT hpet-freq
+
+: get-times  tbl@ pmc1@ f0 hpet@ ;
+
+\ Calculate the CPU and TB frequencies.
+: calibrate  get-times dup >r swap >r swap >r hpet-freq d# 100 / + >r
+             BEGIN get-times dup r@ < WHILE 3drop REPEAT r> drop
+             rot r> - ffffffff and \ TB
+             rot r> - ffffffff and \ CPU
+             rot r> - >r           \ HPET
+             hpet-freq * r@ / swap
+             hpet-freq * r> / ;
+
+: round-to  tuck 2/ + over / * ;
+calibrate TO tb-frequency d# 100000000 round-to TO cpu-frequency
+
+\ Stop HPET.
+0 10 hpet!
-- 
cgit v1.1