收藏本站
Interrupts
The bq4285E/L allows three individually selected inter-
rupt events to generate an interrupt request.
These
three interrupt events are:
n
The periodic interrupt, programmable to occur once
every 122
s to 500 ms.
n
The alarm interrupt, programmable to occur once per
second to once per day, is active in battery-backup
mode, providing a “wake-up” feature.
n
The update-ended interrupt, which occurs at the end
of each update cycle.
Each of the three interrupt events is enabled by an indi-
vidual interrupt-enable bit in register B. When an event
occurs, its event flag bit in register C is set. If the corre-
sponding event enable bit is also set, then an interrupt
request is generated.
The interrupt request flag bit
(INTF) of register C is set with every interrupt request.
Reading register C clears all flag bits, including INTF,
and makes INT high-impedance.
Two methods can be used to process bq4285E/L inter-
rupt events:
n
Enable interrupt events and use the interrupt request
output to invoke an interrupt service routine.
n
Do not enable the interrupts and use a polling routine
to periodically check the status of the flag bits.
The individual interrupt sources are described in detail
in the following sections.
Periodic Interrupt
The mux output used to drive the SQW output also
drives the interrupt-generation circuitry. If the periodic
interrupt event is enabled by writinga1tothe periodic
interrupt enable bit (PIE) in register C, an interrupt re-
quest is generated once every 122
s to 500ms. The pe-
riod between interrupts is selected by the same bits in
register A that select the square wave frequency (see Ta-
ble 3). Setting OSC2–OSC0 in register A to 011 does
not affect the periodic interrupt timing.
6
Register A Bits
Square Wave
Periodic Interrupt
OSC2
OSC1
OSC0
RS3
RS2
RS1
RS0
Frequency
Units
Period
Units
0100000
None
0100001
256
Hz
3.90625
ms
0100010
128
Hz
7.8125
ms
0100011
8.192
kHz
122.070
s
0100100
4.096
kHz
244.141
s
0100101
2.048
kHz
488.281
s
0100110
1.024
kHz
976.5625
s
0100111
512
Hz
1.95315
ms
0101000
256
Hz
3.90625
ms
0101001
128
Hz
7.8125
ms
0101010
64
Hz
15.625
ms
0101011
32
Hz
31.25
ms
0101100
16
Hz
62.5
ms
0101101
8
Hz
125
ms
0101110
4
Hz
250
ms
0101111
2
Hz
500
ms
0
1
XXXX
32.768
kHz
same as above defined
by RS3–RS0
Table 3. Square-Wave Frequency/Periodic Interrupt Rate
bq4285E/L
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
BQ4847YMT IC RTC W/NVSRAM CONTROL T-MOD
BU2280FV-E2 IC CLOCK GEN DVD-VIDEO SSOP-B24
BU2363FV-E2 IC CLOCK GEN DVD-VIDEO SSOP-B16
BU2365FV-E2 IC CLOCK GEN W/VCXO SSOP-B24
BU2505FV-E2 IC DAC 10BIT 10-CHAN SSOP-B20
BU2508FV-E2 IC DAC 10BIT 4-CHAN SSOP14
BU3076HFV-TR IC CLOCK GEN 1CH HVSOF6
CA3338AMZ96 IC DAC 8BIT 50MSPS R-R 16-SOIC
相关代理商/技术参数
BQ4285ES 制造商:未知厂家 制造商全称:未知厂家 功能描述:
BQ4285L 制造商:未知厂家 制造商全称:未知厂家 功能描述:Enhanced RTC With NVRAM Control
BQ4285LP 制造商:TI 制造商全称:Texas Instruments 功能描述:Enhanced RTC With NVRAM Control
BQ4285LQ 制造商:未知厂家 制造商全称:未知厂家 功能描述:
BQ4285LS 制造商:Rochester Electronics LLC 功能描述:- Bulk
BQ4285LSTR 制造商:TI 制造商全称:Texas Instruments 功能描述:Enhanced RTC With NVRAM Control
BQ4285P- 制造商:TI 制造商全称:Texas Instruments 功能描述:Real-Time Clock RTC With NVRAM Control
BQ4285P-SB2 功能描述:实时时钟 RTC IC: 114x8 NVSRAM & NVSRAM Control 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