参数资料
型号: M48T59VMH
厂商: 意法半导体
英文描述: 64 Kbit 8Kb x8 TIMEKEEPER SRAM
中文描述: 64千位8KB的x8 SRAM的计时器
文件页数: 13/21页
文件大小: 168K
代理商: M48T59VMH
13/21
M48T59, M48T59Y, M48T59V
Note:
User must transition address (or toggle chip
enable) to see Flag bit change.
When the clock information matches the alarm
clock settings based on the match criteria defined
by RPT1-RPT4, AF (Alarm Flag) is set. If AFE
(Alarm Flag Enable) is also set, the alarm condi-
tion activates the IRQ/FT pin. To disable alarm,
write ‘0’ to the Alarm Date register and RPT1-4.
The alarm flag and the IRQ/FT output are cleared
by a read to the Flags register.
The IRQ/FT pin can also be activated in the bat-
tery back-up mode. The IRQ/FT will go low if an
alarm occurs and both ABE (Alarm in Battery
Back-up Mode Enable) and AFE are set. The ABE
and AFE bits are reset during power-up, therefore
an alarm generated during power-up will only set
AF. The user can read the Flag Register at system
boot-up to determine if an alarm was generated
while the M48T59 was in the deselect mode during
power-up. Figure 12 illustrates the back-up mode
alarm timing.
WATCHDOG TIMER
The watchdog timer can be used to detect an out-
of-control microprocessor. The user programs the
watchdog timer by setting the desired amount of
time-out into the eight bit Watchdog Register (Ad-
dress 1FF7h). The five bits (BMB4-BMB0) store a
binary multiplier and the two lower order bits (RB1-
RB0) select the resolution, where 00 = 1/16 sec-
ond, 01 = 1/4 second, 10 = 1 second, and 11 = 4
seconds. The amount of time-out is then deter-
mined to be the multiplication of the five bit multi-
plier value with the resolution. (For example:
writing 00001110 in the Watchdog Register = 3 x 1
or 3 seconds).
Note:
Accuracy of timer is within ± the selected
resolution.
If the processor does not reset the timer within the
specified period, the M48T59 sets the WDF
(Watchdog Flag) and generates a watchdog inter-
rupt or a microprocessor reset.
WDF is reset by reading the Flags Register (Ad-
dress 1FFOh).
Figure 12. Back-up Mode Alarm Waveforms
AI03254B
VCC
VPFD (max)
VPFD (min)
IRQ/FT
tREC
ABE, AFE bit in Interrupt Register
AF bit in Flags Register
HIGH-Z
VSO
HIGH-Z
相关PDF资料
PDF描述
M48T59PC 64 Kbit 8Kb x8 TIMEKEEPER SRAM
M48T59V-70MH6TR 64 Kbit 8Kb x8 TIMEKEEPER SRAM
M48T59V-70PC1 64 Kbit 8Kb x8 TIMEKEEPER SRAM
M48T59V-70PC1TR 64 Kbit 8Kb x8 TIMEKEEPER SRAM
M48T59V-70PC6 64 Kbit 8Kb x8 TIMEKEEPER SRAM
相关代理商/技术参数
参数描述
M48T59VPC 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:64 Kbit 8Kb x8 TIMEKEEPER SRAM
M48T59VSH 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:64 Kbit 8Kb x8 TIMEKEEPER SRAM
M48T59Y 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:64 Kbit 8Kb x8 TIMEKEEPER SRAM
M48T59Y-70MH1 功能描述:实时时钟 U 511-M48T59Y-70MH1E RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 总线接口:I2C 日期格式:DW:DM:M:Y 时间格式:HH:MM:SS RTC 存储容量:64 B 电源电压-最大:5.5 V 电源电压-最小:1.8 V 最大工作温度:+ 85 C 最小工作温度: 安装风格:Through Hole 封装 / 箱体:PDIP-8 封装:Tube
M48T59Y-70MH1E 功能描述:实时时钟 64K (8Kx8) 70ns RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 总线接口:I2C 日期格式:DW:DM:M:Y 时间格式:HH:MM:SS RTC 存储容量:64 B 电源电压-最大:5.5 V 电源电压-最小:1.8 V 最大工作温度:+ 85 C 最小工作温度: 安装风格:Through Hole 封装 / 箱体:PDIP-8 封装:Tube