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author fulivi <fulivi@users.noreply.github.com>2015-08-11 14:59:29 +0200
committer fulivi <fulivi@users.noreply.github.com>2015-08-17 10:38:35 +0200
commit8678562f7ec1335b0d2eeb58c38cd2e3785ff24c (patch)
treef9127a9f5b2b08f857350ce6162f8863575f1131 /src
parenta7abd5aaac35af248b46a6ceccef7b704dfba120 (diff)
i8251: rx and tx data buffers separated
Diffstat (limited to 'src')
-rw-r--r--src/emu/machine/i8251.c18
-rw-r--r--src/emu/machine/i8251.h3
2 files changed, 12 insertions, 9 deletions
diff --git a/src/emu/machine/i8251.c b/src/emu/machine/i8251.c
index 362b3372574..e37da9fcb6b 100644
--- a/src/emu/machine/i8251.c
+++ b/src/emu/machine/i8251.c
@@ -107,7 +107,8 @@ void i8251_device::device_start()
save_item(NAME(m_rxc_count));
save_item(NAME(m_txc_count));
save_item(NAME(m_br_factor));
- save_item(NAME(m_data));
+ save_item(NAME(m_rx_data));
+ save_item(NAME(m_tx_data));
save_item(NAME(m_tx_busy));
save_item(NAME(m_disable_tx_pending));
device_serial_interface::register_save_state(machine().save(), this);
@@ -190,7 +191,7 @@ void i8251_device::transmit_clock()
if (is_transmit_register_empty())
{
/* set it up */
- transmit_register_setup(m_data);
+ transmit_register_setup(m_tx_data);
/* i8251 transmit reg now empty */
m_status |=I8251_STATUS_TX_EMPTY;
/* ready for next transmit */
@@ -339,7 +340,8 @@ void i8251_device::device_reset()
m_status = I8251_STATUS_TX_EMPTY | I8251_STATUS_TX_READY;
m_mode_byte = 0;
m_command = 0;
- m_data = 0;
+ m_rx_data = 0;
+ m_tx_data = 0;
m_rxc_count = m_txc_count = 0;
m_br_factor = 1;
m_tx_busy = m_disable_tx_pending = false;
@@ -688,8 +690,9 @@ READ8_MEMBER(i8251_device::status_r)
WRITE8_MEMBER(i8251_device::data_w)
{
- m_data = data;
+ m_tx_data = data;
+ LOG(("data_w %02x\n" , data));
// printf("i8251 transmit char: %02x\n",data);
/* writing clears */
@@ -711,9 +714,8 @@ WRITE8_MEMBER(i8251_device::data_w)
void i8251_device::receive_character(UINT8 ch)
{
-// printf("i8251 receive char: %02x\n",ch);
- m_data = ch;
+ m_rx_data = ch;
/* char has not been read and another has arrived! */
if (m_status & I8251_STATUS_RX_READY)
@@ -733,12 +735,12 @@ void i8251_device::receive_character(UINT8 ch)
READ8_MEMBER(i8251_device::data_r)
{
- //logerror("read data: %02x, STATUS=%02x\n",m_data,m_status);
+ LOG(("read data: %02x, STATUS=%02x\n",m_rx_data,m_status));
/* reading clears */
m_status &= ~I8251_STATUS_RX_READY;
update_rx_ready();
- return m_data;
+ return m_rx_data;
}
diff --git a/src/emu/machine/i8251.h b/src/emu/machine/i8251.h
index 7f51f0dfff2..e2d271a31c3 100644
--- a/src/emu/machine/i8251.h
+++ b/src/emu/machine/i8251.h
@@ -132,7 +132,8 @@ private:
int m_br_factor;
/* data being received */
- UINT8 m_data;
+ UINT8 m_rx_data;
+ UINT8 m_tx_data;
bool m_tx_busy;
bool m_disable_tx_pending;
};