definitions.ice

// 7 bit colour either ALPHA (background or lower layer) or red, green, blue { Arrggbb }
bitfield colour7 {
    uint1   alpha,
    uint2   red,
    uint2   green,
    uint2   blue
}

// 6 bit colour red, green, blue { rrggbb }
bitfield colour6 {
    uint2   red,
    uint2   green,
    uint2   blue
}

bitfield colour13 {
    uint1   alpha,
    uint6   background,
    uint6   foreground,
}

// USED FOR TILEMAP COLOUR ENTRY TO INCLUDE THE REFLECTION FLAGS
bitfield colour15 {
    uint1   y_reflect,
    uint1   x_reflect,
    uint1   alpha,
    uint6   background,
    uint6   foreground,
}

// Vertex in the vector block
bitfield vectorentry {
    uint1   active,
    uint6   dx,                 // 1 sign bit + 5 bits for the offset
    uint6   dy                  // 1 sign bit + 5 bits for the offset
}

// Sprite update flag
bitfield spriteupdate {
    uint1   y_act,              // 1 - kill when off screen, 0 - wrap
    uint1   x_act,              // 1 - kill when off screen, 0 - wrap
    uint1   tile_act,           // 1 - increase the tile number
    uint1   dysign,             // dy - 2's complement update for the y coordinate
    uint4   dy,
    uint1   dxsign,             // dx - 2's complement update for the x coordinate
    uint4   dx
}

// BITFIELD FOR FLOATING POINT CSR REGISTER
bitfield floatingpointcsr{
    uint24  reserved,
    uint3   frm,
    uint5   fflags
}

// ROUNDING MODES
$$ RNE = 0
$$ RTZ = 1
$$ RDN = 2
$$ RUP = 3
$$ RMM = 4

// EXCEPTIONS FLAGS
$$ NX = 1
$$ UF = 2
$$ OF = 4
$$ DZ = 8
$$ NV = 16

// RISC-V BASE INSTRUCTION BITFIELDS
bitfield    Btype {
    uint1   immediate_bits_12,
    uint6   immediate_bits_10_5,
    uint5   sourceReg2,
    uint5   sourceReg1,
    uint3   function3,
    uint4   immediate_bits_4_1,
    uint1   immediate_bits_11,
    uint7   opcode
}

bitfield    Itype {
    uint12  immediate,
    uint5   sourceReg1,
    uint3   function3,
    uint5   destReg,
    uint7   opcode
}

bitfield    ItypeSHIFT {
    uint7   function7,
    uint5   shiftCount,
    uint5   sourceReg1,
    uint3   function3,
    uint5   destReg,
    uint7   opcode
}

bitfield    Jtype {
    uint1   immediate_bits_20,
    uint10  immediate_bits_10_1,
    uint1   immediate_bits_11,
    uint8   immediate_bits_19_12,
    uint5   destReg,
    uint7   opcode
}

bitfield    Rtype {
    uint7   function7,
    uint5   sourceReg2,
    uint5   sourceReg1,
    uint3   function3,
    uint5   destReg,
    uint7   opCode
}
bitfield    R4type {
    uint5   sourceReg3,
    uint2   function2,
    uint5   sourceReg2,
    uint5   sourceReg1,
    uint3   function3,
    uint5   destReg,
    uint7   opCode
}

bitfield Stype {
    uint7   immediate_bits_11_5,
    uint5   sourceReg2,
    uint5   sourceReg1,
    uint3   function3,
    uint5   immediate_bits_4_0,
    uint7   opcode
}

bitfield Utype {
    uint20  immediate_bits_31_12,
    uint5   destReg,
    uint7   opCode
}

// CSR Risc-V Access Instruction
bitfield    CSR {
    uint12  csr,
    uint5   rs1,
    uint3   function3,
    uint5   rd,
    uint7   opcode
}

// COMPRESSED Risc-V Instruction Bitfields
bitfield    CBalu {
    uint3   function3,
    uint1   ib_5,
    uint2   function2,
    uint3   rd_alt,
    uint2   logical2,
    uint3   rs2_alt,
    uint2   opcode
}
bitfield    CBalu50 {
    uint3   function3,
    uint1   ib_5,
    uint2   function2,
    uint3   rd_alt,
    uint5   ib_4_0,
    uint2   opcode
}
bitfield    CB {
    uint3   function3,
    uint1   offset_8,
    uint2   offset_4_3,
    uint3   rs1_alt,
    uint2   offset_7_6,
    uint2   offset_2_1,
    uint1   offset_5,
    uint2   opcode
}

bitfield    CI {
    uint3   function3,
    uint1   ib_5,
    uint5   rd,
    uint3   ib_4_2,
    uint2   ib_7_6,
    uint2   opcode
}
bitfield    CI50 {
    uint3   function3,
    uint1   ib_5,
    uint5   rd,
    uint5   ib_4_0,
    uint2   opcode
}
bitfield    CI94 {
    uint3   function3,
    uint1   ib_9,
    uint5   rd,
    uint1   ib_4,
    uint1   ib_6,
    uint2   ib_8_7,
    uint1   ib_5,
    uint2   opcode
}
bitfield    CIu94 {
    uint3   function3,
    uint2   ib_5_4,
    uint4   ib_9_6,
    uint1   ib_2,
    uint1   ib_3,
    uint3   rd_alt,
    uint2   opcode
}
bitfield    CIlui {
    uint3   function3,
    uint1   ib_17,
    uint5   rd,
    uint5   ib_16_12,
    uint2   opcode
}

bitfield    CJ {
    uint3   function3,
    uint1   ib_11,
    uint1   ib_4,
    uint2   ib_9_8,
    uint1   ib_10,
    uint1   ib_6,
    uint1   ib_7,
    uint3   ib_3_1,
    uint1   ib_5,
    uint2   opcode
}

bitfield    CL {
    uint3   function3,
    uint3   ib_5_3,
    uint3   rs1_alt,
    uint1   ib_2,
    uint1   ib_6,
    uint3   rd_alt,
    uint2   opcode
}

bitfield    CR {
    uint4   function4,
    uint5   rs1,
    uint5   rs2,
    uint2   opcode
}

bitfield    CS {
    uint3   function3,
    uint1   ib_5,
    uint2   ib_4_3,
    uint3   rs1_alt,
    uint1   ib_2,
    uint1   ib_6,
    uint3   rs2_alt,
    uint2   opcode
}

bitfield    CSS {
    uint3   function3,
    uint1   ib_5,
    uint3   ib_4_2,
    uint2   ib_7_6,
    uint5   rs2,
    uint2   opcode
}