// license:BSD-3-Clause // copyright-holders:Ryan Holtz /***************************************************************************** SunPlus SPG2xx-series SoC peripheral emulation (System DMA) **********************************************************************/ #include "emu.h" #include "spg2xx_sysdma.h" DEFINE_DEVICE_TYPE(SPG2XX_SYSDMA, spg2xx_sysdma_device, "spg2xx_sysdma", "SPG240-series System-on-a-Chip System DMA") #define LOG_DMA (1U << 9) #define LOG_ALL (LOG_DMA) #define VERBOSE (0) #include "logmacro.h" spg2xx_sysdma_device::spg2xx_sysdma_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : device_t(mconfig, SPG2XX_SYSDMA, tag, owner, clock) , m_cpu(*this, finder_base::DUMMY_TAG) { } void spg2xx_sysdma_device::device_start() { save_item(NAME(m_dma_regs)); } void spg2xx_sysdma_device::device_reset() { memset(m_dma_regs, 0, 0x4 * sizeof(uint16_t)); } /************************* * Machine Hardware * *************************/ READ16_MEMBER(spg2xx_sysdma_device::dma_r) { offset &= 0x3; uint16_t val = m_dma_regs[offset]; switch (offset) { case 0x000: // DMA Source (L) LOGMASKED(LOG_DMA, "dma_r: DMA Source (lo) = %04x\n", val); break; case 0x001: // DMA Source (H) LOGMASKED(LOG_DMA, "dma_r: DMA Source (hi) = %04x\n", val); break; case 0x002: // DMA Length LOGMASKED(LOG_DMA, "dma_r: DMA Length = %04x\n", 0); val = 0; break; case 0x003: // DMA Destination LOGMASKED(LOG_DMA, "dma_r: DMA Dest = %04x\n", val); break; } return val; } WRITE16_MEMBER(spg2xx_sysdma_device::dma_w) { offset &= 0x3; switch (offset) { case 0x000: // DMA Source (lo) LOGMASKED(LOG_DMA, "dma_w: DMA Source (lo) = %04x\n", data); m_dma_regs[offset] = data; break; case 0x001: // DMA Source (hi) LOGMASKED(LOG_DMA, "dma_w: DMA Source (hi) = %04x\n", data); m_dma_regs[offset] = data; break; case 0x002: // DMA Length LOGMASKED(LOG_DMA, "dma_w: DMA Length = %04x\n", data); if (!(data & 0xc000)) // jak_dora writes 0xffff here which ends up trashing registers etc. why? such writes can't be valid do_cpu_dma(data); break; case 0x003: // DMA Destination LOGMASKED(LOG_DMA, "dma_w: DMA Dest = %04x\n", data); m_dma_regs[offset] = data; break; } } void spg2xx_sysdma_device::do_cpu_dma(uint32_t len) { address_space &mem = m_cpu->space(AS_PROGRAM); uint32_t src = ((m_dma_regs[0x001] & 0x3f) << 16) | m_dma_regs[0x000]; uint32_t dst = m_dma_regs[0x003] & 0x3fff; for (uint32_t j = 0; j < len; j++) { mem.write_word((dst + j) & 0x3fff, mem.read_word(src + j)); } src += len; m_dma_regs[0x000] = (uint16_t)src; m_dma_regs[0x001] = (src >> 16) & 0x3f; m_dma_regs[0x002] = 0; m_dma_regs[0x003] = (dst + len) & 0x3fff; }