m48t59y.c
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上传用户:yuanda199
上传日期:2022-06-26
资源大小:412k
文件大小:7k
源码类别:
VxWorks
开发平台:
C/C++
- /*
- * $Id: m48t59y.c,v 1.1 Broadcom SDK $
- *
- * SGS M48-T59Y TOD/NVRAM Driver
- *
- * The SGS M48 an 8K NVRAM starting at offset M48_BASE_ADDR and
- * continuing for 8176 bytes. After that starts the Time-Of-Day (TOD)
- * registers which are used to set/get the internal date/time functions.
- *
- * This module implements Y2K compliance by taking full year numbers
- * and translating back and forth from the TOD 2-digit year.
- *
- * NOTE: for proper interaction with an operating system, the TOD should
- * be used to store Universal Coordinated Time (GMT) and timezone
- * conversions should be used.
- *
- * Here is a diagram of the memory layout:
- *
- * +---------------------------------------------+ 0xffe0a000
- * | Non-volatile memory | .
- * | | .
- * | (8176 bytes of Non-volatile memory) | .
- * | | .
- * +---------------------------------------------+ 0xffe0bff0
- * | Flags |
- * +---------------------------------------------+ 0xffe0bff1
- * | Unused |
- * +---------------------------------------------+ 0xffe0bff2
- * | Alarm Seconds |
- * +---------------------------------------------+ 0xffe0bff3
- * | Alarm Minutes |
- * +---------------------------------------------+ 0xffe0bff4
- * | Alarm Date |
- * +---------------------------------------------+ 0xffe0bff5
- * | Interrupts |
- * +---------------------------------------------+ 0xffe0bff6
- * | WatchDog |
- * +---------------------------------------------+ 0xffe0bff7
- * | Calibration |
- * +---------------------------------------------+ 0xffe0bff8
- * | Seconds |
- * +---------------------------------------------+ 0xffe0bff9
- * | Minutes |
- * +---------------------------------------------+ 0xffe0bffa
- * | Hours |
- * +---------------------------------------------+ 0xffe0bffb
- * | Day |
- * +---------------------------------------------+ 0xffe0bffc
- * | Date |
- * +---------------------------------------------+ 0xffe0bffd
- * | Month |
- * +---------------------------------------------+ 0xffe0bffe
- * | Year (2 digits only) |
- * +---------------------------------------------+ 0xffe0bfff
- */
- #include "vxWorks.h"
- #include "mbz.h"
- /*
- * Imported from mbz.h:
- *
- * TOD_REG_BASE Base of m48t59y TOD registers
- * SYS_TOD_UNPROTECT() Disable NVRAM write protect
- * SYS_TOD_PROTECT() Re-enable NVRAM write protect
- */
- #define YEAR (0xf^0x3)
- #define MONTH (0xe^0x3)
- #define DAY (0xd^0x3)
- #define DAY_OF_WEEK (0xc^0x3)
- #define HOUR (0xb^0x3)
- #define MINUTE (0xa^0x3)
- #define SECOND (0x9^0x3)
- #define CONTROL (0x8^0x3)
- #define WATCH (0x7^0x3)
- #define INTCTL (0x6^0x3)
- #define WD_DATE (0x5^0x3)
- #define WD_HOUR (0x4^0x3)
- #define WD_MIN (0x3^0x3)
- #define WD_SEC (0x2^0x3)
- #define _UNUSED (0x1^0x3)
- #define FLAGS (0x0^0x3)
- static UINT8 *m48BaseAddr;
- #define M48_ADDR ((volatile UINT8 *) (m48BaseAddr + 8*1024 - 16))
- STATUS m48_tod_init(UINT8 *addr)
- {
- m48BaseAddr = addr;
- SYS_TOD_UNPROTECT();
- M48_ADDR[CONTROL] = 0;
- M48_ADDR[WATCH] = 0;
- M48_ADDR[INTCTL] = 0;
- /*
- * If the oscillator is currently stopped (as on a new part shipped
- * from the factory), start it running.
- *
- * Here is an example of the TOD bytes on a brand new M48T59Y part:
- * 00 00 00 00 00 00 00 00 00 88 8c c3 bf c8 f5 01
- */
- if (M48_ADDR[SECOND] & 0x80)
- M48_ADDR[SECOND] = 0;
- SYS_TOD_PROTECT();
- return OK;
- }
- /*
- * m48_tod_set
- */
- static int to_bcd(int value)
- {
- return value / 10 * 16 + value % 10;
- }
- static int from_bcd(int value)
- {
- return value / 16 * 10 + value % 16;
- }
- static int day_of_week(int y, int m, int d) /* 0-6 ==> Sun-Sat */
- {
- static int t[] = {0, 3, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4};
- y -= m < 3;
- return (y + y/4 - y/100 + y/400 + t[m-1] + d) % 7;
- }
- /*
- * Note: the TOD should store the current GMT
- */
- STATUS m48_tod_set(int year, /* 1980-2079 */
- int month, /* 01-12 */
- int day, /* 01-31 */
- int hour, /* 00-23 */
- int minute, /* 00-59 */
- int second) /* 00-59 */
- {
- SYS_TOD_UNPROTECT();
- M48_ADDR[CONTROL] |= 0x80; /* Set WRITE bit */
- M48_ADDR[YEAR] = to_bcd(year % 100);
- M48_ADDR[MONTH] = to_bcd(month);
- M48_ADDR[DAY] = to_bcd(day);
- M48_ADDR[DAY_OF_WEEK] = day_of_week(year, month, day) + 1;
- M48_ADDR[HOUR] = to_bcd(hour);
- M48_ADDR[MINUTE] = to_bcd(minute);
- M48_ADDR[SECOND] = to_bcd(second);
- M48_ADDR[CONTROL] &= ~0x80; /* Clear WRITE bit */
- SYS_TOD_PROTECT();
- return OK;
- }
- /*
- * Note: the TOD should store the current GMT
- */
- STATUS m48_tod_get(int *year, /* 1980-2079 */
- int *month, /* 01-12 */
- int *day, /* 01-31 */
- int *hour, /* 00-23 */
- int *minute, /* 00-59 */
- int *second) /* 00-59 */
- {
- int y;
- SYS_TOD_UNPROTECT();
- M48_ADDR[CONTROL] |= 0x40; /* Set READ bit */
- y = from_bcd(M48_ADDR[YEAR]);
- *year = y < 80 ? 2000 + y : 1900 + y;
- *month = from_bcd(M48_ADDR[MONTH]);
- *day = from_bcd(M48_ADDR[DAY]);
- /* day_of_week = M48_ADDR[DAY_OF_WEEK] & 0xf; */
- *hour = from_bcd(M48_ADDR[HOUR]);
- *minute = from_bcd(M48_ADDR[MINUTE]);
- *second = from_bcd(M48_ADDR[SECOND] & 0x7f);
- M48_ADDR[CONTROL] &= ~0x40; /* Clear READ bit */
- SYS_TOD_PROTECT();
- return OK;
- }
- int m48_tod_get_second(void)
- {
- return from_bcd(M48_ADDR[SECOND] & 0x7f);
- }
- /*
- * Watchdog function
- *
- * If usec is 0, the watchdog timer is disarmed.
- *
- * If usec is non-zero, the watchdog timer is armed (or re-armed) for
- * approximately usec microseconds (if the exact requested usec is
- * not supported by the chip, the next higher available value is used).
- *
- * Minimum watchdog timeout = 62500 usec
- * Maximum watchdog timeout = 124 sec (124000000 usec)
- */
- void m48_watchdog_arm(int usec)
- {
- int mpy, res;
- SYS_TOD_UNPROTECT();
- if (usec == 0) {
- res = 0;
- mpy = 0;
- } else if (usec < 2000000) { /* Resolution: 1/16s if below 2s */
- res = 0;
- mpy = (usec + 62499) / 62500;
- } else if (usec < 8000000) { /* Resolution: 1/4s if below 8s */
- res = 1;
- mpy = (usec + 249999) / 250000;
- } else if (usec < 32000000) { /* Resolution: 1s if below 32s */
- res = 2;
- mpy = (usec + 999999) / 1000000;
- } else { /* Resolution: 4s up to 124s */
- res = 3;
- mpy = (usec + 3999999) / 4000000;
- if (mpy > 31)
- mpy = 31;
- }
- M48_ADDR[WATCH] = (0x80 | /* Steer to RST signal (IRQ = N/C) */
- mpy << 2 |
- res);
- SYS_TOD_PROTECT();
- }