diff options
Diffstat (limited to 'qtmips_machine/serialport.cpp')
-rw-r--r-- | qtmips_machine/serialport.cpp | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/qtmips_machine/serialport.cpp b/qtmips_machine/serialport.cpp index 9e4177b..c636d38 100644 --- a/qtmips_machine/serialport.cpp +++ b/qtmips_machine/serialport.cpp @@ -51,6 +51,7 @@ using namespace machine; SerialPort::SerialPort() { rx_st_reg = 0; + rx_data_reg = 0; tx_st_reg = 0; } @@ -58,6 +59,18 @@ SerialPort::~SerialPort() { } +void SerialPort::pool_rx_byte() const { + unsigned int byte = 0; + bool available = false; + if (!(rx_st_reg & SERP_RX_ST_REG_READY_m)) { + emit rx_byte_pool(0, byte, available); + if (available) { + rx_data_reg = byte; + rx_st_reg |= SERP_RX_ST_REG_READY_m; + } + } +} + bool SerialPort::wword(std::uint32_t address, std::uint32_t value) { #if 0 printf("SerialPort::wword address 0x%08lx data 0x%08lx\n", @@ -90,10 +103,17 @@ std::uint32_t SerialPort::rword(std::uint32_t address, bool debug_access) const #endif switch (address) { case SERP_RX_ST_REG_o: + pool_rx_byte(); value = rx_st_reg; break; case SERP_RX_DATA_REG_o: - value = 0; + pool_rx_byte(); + if (rx_st_reg & SERP_RX_ST_REG_READY_m) { + value = rx_data_reg; + rx_st_reg &= ~SERP_RX_ST_REG_READY_m; + } else { + value = 0; + } break; case SERP_TX_ST_REG_o: value = tx_st_reg | SERP_TX_ST_REG_READY_m; |