aos/devices/lpc_timer.dev
Daniel Schwyn 6d444bf552 Main handout
Signed-off-by: Daniel Schwyn <daniel.schwyn@inf.ethz.ch>
2022-03-03 14:57:51 +01:00

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/*
* Copyright (c) 2007, 2008, ETH Zurich. All rights reserved.
*
* This file is distributed under the terms in the attached LICENSE file.
* If you do not find this file, copies can be found by writing to:
* ETH Zurich D-INFK, Universitaetstrasse 6, CH-8092 Zurich. Attn: Systems Group.
*/
/*
* lpc_timer.dev
*
* DESCRIPTION: Legacy timer registers on the LPC (low pin count, or
* legacy PC) bridge function of a typical Intel IHC
* (Southbridge).
*
* This is derived from the "Intel 631xESB/632xESB IO/Controller Hub
* Datasheet", chapter 21, "LPC Interface Bridge Registers (D31:F0)".
*/
device lpc_timer (io base) "LPC Timer" {
//
// Section 21.3: Timer I/O registers
//
constants cnt_mode "Counter mode" {
oseoc = 0b000 "Out signal on end of count (mode 0)";
hr1s = 0b001 "Hardware retriggerable one-shot (mode 1)";
rtgen = 0b010 "Rate generator (mode 2)";
rtgen_ = 0b110 "Rate generator (mode 2)";
sqwav = 0b011 "Square wave output (mode 3)";
sqwav_ = 0b111 "Square wave output (mode 3)";
swstr = 0b100 "Software triggered strobe (mode 4)";
hwstr = 0b101 "Hardware triggered strobe (mode 5)";
};
constants timer_rwsel "Read/write select" {
clc = 0b00 "Counter latch cmd";
lsb = 0b01 "R/w least sig. byte";
msb = 0b10 "R/w most sig. byte";
lmsb = 0b11 "R/w lsb then msb";
};
constants timer_cntsel "Counter select" {
c0 = 0b00 "Counter 0";
c1 = 0b01 "Counter 1";
c2 = 0b10 "Counter 2";
rb = 0b11 "Read back cmd";
};
register tcw wo io( base, 0x3 ) "Timer Control Word" {
bcd 1 "Binary coded decimal select";
mode 3 type(cnt_mode) "Counter mode";
rwsel 2 type(timer_rwsel) "Read/write select";
select 2 type(timer_cntsel) "Counter select";
};
register rdbk_cmd wo also io( base, 0x3 ) "Read back command" {
_ 1 mbz;
c0 1 "Counter 0 select";
c1 1 "Counter 1 select";
c2 1 "Counter 2 select";
stat 1 "Latch status of selected counters";
count 1 "Latch count of selected counters";
_ 2 mb1;
};
register ltch_cmd wo also io( base, 0x3 ) "Counter latch command" {
_ 6 mbz;
select 2 type(timer_cntsel) "Counter select";
};
regtype sbyte_fmt "Interval timer status byte format" {
bcd 1 "Binary coded decimal select";
mode 3 type(cnt_mode) "Counter mode";
rwsel 2 type(timer_rwsel) "Read/write select";
cnt_stat 1 "Count register status";
cnt_out 1 "Counter OUT pin status";
};
register sbyte_fmt0 ro io( base, 0x0 ) "Int. timer 0 status format" type(sbyte_fmt);
register sbyte_fmt1 ro io( base, 0x1 ) "Int. timer 1 status format" type(sbyte_fmt);
register sbyte_fmt2 ro io( base, 0x2 ) "Int. timer 2 status format" type(sbyte_fmt);
register cntacc0 rw also io( base, 0x0 ) "Counter 0 access" type(uint8);
register cntacc1 rw also io( base, 0x1 ) "Counter 1 access" type(uint8);
register cntacc2 rw also io( base, 0x2 ) "Counter 2 access" type(uint8);
};