UINT8 pia6821_device::port_b_r() { UINT8 ret = get_in_b_value(); // This read will implicitly clear the IRQ B1 flag. If CB2 is in write-strobe // mode with CB1 restore, and a CB1 active transition set the flag, // clearing it will cause CB2 to go high again. Note that this is different // from what happens with port A. if(m_irq_b1 && C2_STROBE_MODE(m_ctl_b) && STROBE_C1_RESET(m_ctl_b)) { set_out_cb2(TRUE); } // IRQ flags implicitly cleared by a read m_irq_b1 = FALSE; m_irq_b2 = FALSE; update_interrupts(); LOG(("PIA #%s: port B read = %02X\n", tag(), ret)); return ret; }
static UINT8 port_b_r(const device_config *device) { pia6821_state *p = get_token(device); UINT8 ret = get_in_b_value(device); /* This read will implicitly clear the IRQ B1 flag. If CB2 is in write-strobe mode with CB1 restore, and a CB1 active transition set the flag, clearing it will cause CB2 to go high again. Note that this is different from what happens with port A. */ if (p->irq_b1 && C2_STROBE_MODE(p->ctl_b) && STROBE_C1_RESET(p->ctl_b)) set_out_cb2(device, TRUE); /* IRQ flags implicitly cleared by a read */ p->irq_b1 = FALSE; p->irq_b2 = FALSE; update_interrupts(device); LOG(("PIA #%s: port B read = %02X\n", device->tag, ret)); return ret; }