dali/bacnet_stack
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Added comments.

Browse Source
This commit is contained in:
skarg
2010-08-23 14:03:06 +00:00
parent 298038c0d8
commit fd22542ad1
1 changed files with 5 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files
bacnet-stack/ports/bdk-atxx4-mstp/seeprom.c
+5 -2
View File
@@ -1,6 +1,7 @@
/************************************************************************** /**************************************************************************
* *
* Copyright (C) 2009 Steve Karg <skarg@users.sourceforge.net> * Copyright (C) 2009 Steve Karg <skarg@users.sourceforge.net>
* Used algorithm and code from Joerg Wunsch and Ruwan Jayanetti.
* *
* Permission is hereby granted, free of charge, to any person obtaining * Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the * a copy of this software and associated documentation files (the
@@ -420,8 +421,8 @@ static int seeprom_bytes_write_page(
* byte is placed at the beginning of the same * byte is placed at the beginning of the same
* page. If more than 64 data words are * page. If more than 64 data words are
* transmitted to the EEPROM, the data word * transmitted to the EEPROM, the data word
* address will “roll over” and previous data will be * address will "roll over" and previous data will be
* overwritten. The address “roll over” during write * overwritten. The address "roll over" during write
* is from the last byte of the current page to the * is from the last byte of the current page to the
* first byte of the same page. * first byte of the same page.
**************************************************************************/ **************************************************************************/
@@ -462,6 +463,8 @@ void seeprom_init(
TWSR = 0; TWSR = 0;
TWCR = _BV(TWEN) | _BV(TWEA); TWCR = _BV(TWEN) | _BV(TWEA);
/* bit rate */ /* bit rate */
/* SCL freq = F_CPU/(16+2*TWBR*4^TWPS) */
/* since TWPS in TWSR is set to zero, 4^TWPS resolves to 1 */
TWBR = (F_CPU / SEEPROM_I2C_CLOCK - 16) / 2; TWBR = (F_CPU / SEEPROM_I2C_CLOCK - 16) / 2;
/* my address */ /* my address */
TWAR = 0; TWAR = 0;