 |
数据搜索系统，热门电子元器件搜索 |
|
|
数据搜索系统，热门电子元器件搜索 |
|
PCF8523T 数据表(PDF) 33 Page - NXP Semiconductors |
|
|
|||||||||||||||||||||||||||||
PCF8523T 数据表(HTML) 33 Page - NXP Semiconductors |
|
|
33 / 75 page  PCF8523 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved. Product data sheet Rev. 4 — 5 July 2012 33 of 74 NXP Semiconductors PCF8523 Real-Time Clock (RTC) and calendar A programmable square wave is available at pin INT1/CLKOUT and pin CLKOUT, which are both open-drain outputs. Pin INT1/CLKOUT has both functions of INT1 and CLKOUT combined. The duty cycle of the selected clock is not controlled but due to the nature of the clock generation, all clock frequencies except 32.768 kHz have a duty cycle of 50 : 50. The STOP bit function can also affect the CLKOUT signal, depending on the selected frequency. When STOP is active, the INT1/CLKOUT and CLKOUT pins are high-impedance for all frequencies except of 32.768 kHz, 16.384 kHz and 8.192 kHz. For more details, see Section 8.10. [1] Duty cycle definition: % HIGH-level time : % LOW-level time. [2] Default value. [3] Clock frequencies may be affected by offset correction. 8.9.1.3 Register Tmr_A_freq_ctrl [1] Default value. Table 35. CLKOUT frequency selection COF[2:0] CLKOUT frequency (Hz) Typical duty cycle[1] Effect of STOP bit 000[2] 32768 60 : 40 to 40 : 60 no effect 001 16384 50 : 50 no effect 010 8192 50 : 50 no effect 011 4096 50 : 50 CLKOUT = high-Z 100 1024 50 : 50 CLKOUT = high-Z 101 32 50 : 50[3] CLKOUT = high-Z 110 1 50 : 50[3] CLKOUT = high-Z 111 CLKOUT disabled (high-Z) Table 36. Tmr_A_freq_ctrl - timer A frequency control register (address 10h) bit description Bit Symbol Value Description 7 to 3 - - unused 2 to 0 TAQ[2:0] source clock for timer A (see Table 40) 000 4.096 kHz 001 64 Hz 010 1 Hz 011 1⁄60 Hz 111[1] 110 100 1⁄3600 Hz |
|
链接网址 |
| ALLDATASHEET是否为您带来帮助? [ DONATE ] |
关于 Alldatasheet | 广告服务 | 联系我们 | 隐私政策 | 数据表链接 | 链接交换 | 制造商名单 All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
Chinese ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
