| 数据搜索系统,热门电子元器件搜索 |
|
Z8018233FSC 数据表(PDF) 76 Page - Zilog, Inc. |
|
|
|||||||||||||||||||||||||||||
Z8018233FSC 数据表(HTML) 76 Page - Zilog, Inc. |
|
76 / 109 page ![]() 3-76 Z80182/Z8L182 ZILOG INTELLIGENT PERIPHERAL PRELIMINARY Zilog DS971820600 PARALLEL PORTS REGISTERS The Z80182/Z8L182 has three 8-bit bi-directional Ports. Each bit is individually programmable for input or output. The Ports consist of two registers the Port Direction Control Register and the Port Data Register. The Port and direction register can be accessed in any page of I/O space since only the lowest eight address lines are decoded. Bits PC7 and PC6 are input only bits and have the special function of reading the external value of the /INT2 and /INT1 pins. Writing ‘1’ to these bits will clear the edge detect interrupt logic when operating /INT2 and/or /INT1 in edge detect mode. When Port B and Port C bits 5-0 are deselected in the System Configuration Register, the Data and Data Direction Registers are still available as read/write scratch registers. If a Port is deselected and if the DDR bit is a ‘0’, then the written value to that bit will be latched and this value can be read back. If a Port is deselected and if the DDR bit is a ‘1’, then you could read only the external pin value; any write to that bit is latched but can be read back only with DDR=0. 1 1 11111 1 D7 D6 D5 D4 D3 D2 D1 D0 PB Data Direction Register 0=Output 1=Input 1 1 11111 1 D7 D6 D5 D4 D3 D2 D1 D0 PA Data Direction Register 0=Output 1=Input Figure 83. PA, Port A, Data Direction Register (Z180 MPU Read/Write, Address xxEDH) The data direction register determines which are inputs and outputs in the PA Data Register. When a bit is set to 1 the corresponding bit in the PA Data Register is an input. If the bit is 0, then the corresponding bit is an output. X XXXX XXX D7 D6 D5 D4 D3 D2 D1 D0 PA Data Register Figure 84. PA, Port A, Data Register (Z180 MPU Read/Write, Address xxEEH) When the Z180 MPU writes to the PA Data Register the data is stored in the internal buffer. The values of the PA Data Register are undefined after reset. Any bits that are output are then sent on to the output buffers. When the Z180 MPU reads the PA Data Register the data on the external pins is returned. Figure 85. PB, Port B, Data Direction Register (Z180 MPU Read/Write, Address xxE4H) The data direction register determines which are inputs and outputs in the PB Data Register. When a bit is set to 1 the corresponding bit in the PB Data Register is an input. If the bit is 0 then the corresponding bit is an output. Figure 86. PB, Port B, Data Register (Z180 MPU, Address xxE5H) When the Z180 MPU writes to the PB Data Register the data is stored in the internal buffer. The values of Port B data register are undefined after reset. Any bits that are output are then sent on to the output buffers. When the Z180 MPU reads the PB Data Register, the data on the external pins is returned. X X X X X XXX D7 D6 D5 D4 D3 D2 D1 D0 PB Data Register X X 11111 1 D7 D6 D5 D4 D3 D2 D1 D0 PC Direction Register Figure 87. PC, Port C, Data Direction Register (Z180 MPU Read/Write, Address xxDDH) |
|
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 |