Rainbow Electronics AT89C5122 - Manual (Page 56)

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AT8xC5122/23
4202E–SCR–06/06
Port 4 Port 4 has the following functions:
– Default function: Port 4 is an 6-bit I/O port.
– Alternate functions: see table below
Port 4 has the following configurations:
– Default configuration: Pseudo bi-directional “Port51” digital input/output with
internal pull-ups.
– Alternate configurations: See Table 33.
Table 33. Port 4 Description
Port 5 Port 5 has the following functions:
– Default function: Port 5 is an 8-bit I/O port.
– Alternate function 1: Port 5 is an 8-bit keyboard port KB0 to KB7.
Port 5 has the following configurations:
– Default configuration: Pseudo bi-directional “Port51” digital input/output with
internal pull-ups.
– Alternate configuration: see Table 34.
Table 34. Port 5 Description
Port
Alternate Functions Configurations
Signal Description Mode 1 Mode 2 Mode 3
P4.0 MISO SPI Master In Slave Out I/O
P4.1 MOSI SPI Master Out Slave In I/O
P4.2 SCK SPI clock
P4.3 Push-pull KB_OUT Input MPU
P4.4 Push-pull KB_OUT Input MPU
P4.5 Push-pull KB_OUT Input MPU
Port
Configurations
Mode 1 Mode 2 Mode 3 Comments
P5.0 Push-pull Input MPU Input WPU
First cluster P5.1 Push-pull Input MPU Input WPU
P5.2 Push-pull Input MPU Input WPU
P5.3 Push-pull Input WPD Input WPU
Second cluster
P5.4 Push-pull Input WPD Input WPU
P5.5 Push-pull Input WPD Input WPU
P5.6 Push-pull Input WPD Input WPU
Third cluster
P5.7 Push-pull Input WPD Input WPU