/********************************************************************** MM74C922/MM74C923 16/20-Key Encoder emulation Copyright MESS Team. Visit http://mamedev.org for licensing and usage restrictions. ********************************************************************** _____ _____ ROW Y1 1 |* \_/ | 18 Vcc ROW Y2 2 | | 17 DATA OUT A ROW Y3 3 | | 16 DATA OUT B ROW Y4 4 | | 15 DATA OUT C OSCILLATOR 5 | MM74C922 | 14 DATA OUT D KEYBOUNCE MASK 6 | | 13 _OUTPUT ENABLE COLUMN X4 7 | | 12 DATA AVAILABLE COLUMN X3 8 | | 11 COLUMN X1 GND 9 |_____________| 10 COLUMN X2 _____ _____ ROW Y1 1 |* \_/ | 20 Vcc ROW Y2 2 | | 19 DATA OUT A ROW Y3 3 | | 18 DATA OUT B ROW Y4 4 | | 17 DATA OUT C ROW Y5 5 | MM74C923 | 16 DATA OUT D OSCILLATOR 6 | | 15 DATA OUT E KEYBOUNCE MASK 7 | | 14 _OUTPUT ENABLE COLUMN X4 8 | | 13 DATA AVAILABLE COLUMN X3 9 | | 12 COLUMN X1 GND 10 |_____________| 11 COLUMN X2 **********************************************************************/ #pragma once #ifndef __MM74C922__ #define __MM74C922__ #include "emu.h" //************************************************************************** // INTERFACE CONFIGURATION MACROS //************************************************************************** #define MCFG_MM74C922_ADD(_tag, _config) \ MCFG_DEVICE_ADD(_tag, MM74C922, 0) \ MCFG_DEVICE_CONFIG(_config) \ mm74c922_device::static_set_config(*device, 4); #define MCFG_MM74C923_ADD(_tag, _config) \ MCFG_DEVICE_ADD(_tag, MM74C923, 0) \ MCFG_DEVICE_CONFIG(_config) \ mm74c922_device::static_set_config(*device, 5); #define MM74C922_INTERFACE(name) \ const mm74c922_interface (name)= #define MM74C923_INTERFACE(name) \ const mm74c922_interface (name)= //************************************************************************** // TYPE DEFINITIONS //************************************************************************** // ======================> mm74c922_interface struct mm74c922_interface { double m_cap_osc; double m_cap_debounce; devcb_write_line m_out_da_cb; devcb_read8 m_in_x1_cb; devcb_read8 m_in_x2_cb; devcb_read8 m_in_x3_cb; devcb_read8 m_in_x4_cb; devcb_read8 m_in_x5_cb; }; // ======================> mm74c922_device class mm74c922_device : public device_t, public mm74c922_interface { public: // construction/destruction mm74c922_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock); // inline configuration helpers static void static_set_config(device_t &device, int max_y); UINT8 data_out_r(); protected: // device-level overrides virtual void device_config_complete(); virtual void device_start(); virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr); private: inline void change_output_lines(); inline void clock_scan_counters(); inline void detect_keypress(); int m_max_y; devcb_resolved_write_line m_out_da_func; devcb_resolved_read8 m_in_x_func[5]; int m_inhibit; // scan counter clock inhibit int m_x; // currently scanned column int m_y; // latched row UINT8 m_data; // data latch int m_da; // data available flag int m_next_da; // next value of data available flag // timers emu_timer *m_scan_timer; // keyboard scan timer }; // device type definition extern const device_type MM74C922; extern const device_type MM74C923; #endif