summaryrefslogtreecommitdiffstatshomepage
path: root/src/mess/machine/mc6854.h
diff options
context:
space:
mode:
author Miodrag Milanovic <mmicko@gmail.com>2012-08-21 10:41:19 +0000
committer Miodrag Milanovic <mmicko@gmail.com>2012-08-21 10:41:19 +0000
commit7285b359d259b2ae0fdf85096571c386ec8c991a (patch)
treea027aff57f1a255f9ec6cfd3b68cabe4b6683998 /src/mess/machine/mc6854.h
parent67c425e90757876a6716b7867df30c0149912e74 (diff)
Merge of MESS sources (no whatsnew)
Diffstat (limited to 'src/mess/machine/mc6854.h')
-rw-r--r--src/mess/machine/mc6854.h82
1 files changed, 82 insertions, 0 deletions
diff --git a/src/mess/machine/mc6854.h b/src/mess/machine/mc6854.h
new file mode 100644
index 00000000000..e0b13373625
--- /dev/null
+++ b/src/mess/machine/mc6854.h
@@ -0,0 +1,82 @@
+/**********************************************************************
+
+ Copyright (C) Antoine Mine' 2006
+
+ Motorola 6854 emulation (network interface).
+
+**********************************************************************/
+
+#ifndef MC6854_H
+#define MC6854_H
+
+DECLARE_LEGACY_DEVICE(MC6854, mc6854);
+
+/* we provide two interfaces:
+ - a bit-based interface: out_tx, set_rx
+ - a frame-based interface: out_frame, send_frame
+
+ The bit-based interface is low-level and slow.
+ Use it to simulate the actual bits sent into the wires, e.g., to connect
+ the emulator to another bit-based emulated network device, or an actual
+ device.
+
+ The frame-based interface is higher-level and faster.
+ It passes bytes directly from one end to the other without bothering with
+ the actual bit-encoding, synchronization, and CRC.
+ Once completed, a frame is sent through out_frame. Aborted frames are not
+ transmitted at all. No start flag, stop flag, or crc bits are trasmitted.
+ send_frame makes a frame available to the CPU through the 6854 (it may
+ fail and return -1 if the 6854 is not ready to accept the frame; even
+ if the frame is accepted and 0 is returned, the CPU may abort it). Ony
+ full frames are accepted.
+*/
+
+
+/* ---------- configuration ------------ */
+
+typedef struct _mc6854_interface mc6854_interface;
+struct _mc6854_interface
+{
+ devcb_write_line out_irq_func; /* interrupt request */
+
+ /* low-level, bit-based interface */
+ devcb_read_line in_rxd_func; /* receive bit */
+ devcb_write_line out_txd_func; /* transmit bit */
+
+ /* high-level, frame-based interface */
+ void ( * out_frame ) ( device_t *device, UINT8* data, int length );
+
+ /* control lines */
+ devcb_write_line out_rts_func; /* 1 = transmitting, 0 = idle */
+ devcb_write_line out_dtr_func; /* 1 = data transmit ready, 0 = busy */
+};
+
+
+#define MCFG_MC6854_ADD(_tag, _intrf) \
+ MCFG_DEVICE_ADD(_tag, MC6854, 0) \
+ MCFG_DEVICE_CONFIG(_intrf)
+
+#define MCFG_MC6854_REMOVE(_tag) \
+ MCFG_DEVICE_REMOVE(_tag)
+
+
+/* ---------- functions ------------ */
+/* interface to CPU via address/data bus*/
+extern READ8_DEVICE_HANDLER ( mc6854_r );
+extern WRITE8_DEVICE_HANDLER ( mc6854_w );
+
+/* low-level, bit-based interface */
+WRITE_LINE_DEVICE_HANDLER( mc6854_set_rx );
+
+/* high-level, frame-based interface */
+extern int mc6854_send_frame( device_t *device, UINT8* data, int length ); /* ret -1 if busy */
+
+/* control lines */
+WRITE_LINE_DEVICE_HANDLER( mc6854_set_cts ); /* 1 = clear-to-send, 0 = busy */
+WRITE_LINE_DEVICE_HANDLER( mc6854_set_dcd ); /* 1 = carrier, 0 = no carrier */
+
+/* clock */
+WRITE_LINE_DEVICE_HANDLER( mc6854_rxc_w );
+WRITE_LINE_DEVICE_HANDLER( mc6854_txc_w );
+
+#endif