| IC number: | MC68851 (XC68851) |
| IC function: | PMMU (Paged Memory Management Unit) |
| Related components: | MC68020 (main processor), MC68030 , MC68040 (successors, on-chip MMU) |
| IC number | Manufacturer | Documentation |
|---|---|---|
| MC68851 (XC68851) | Motorola | M68000 family reference (book) |
| IC number | Package | Speed |
|---|---|---|
| MC68851RC16 (XC68851RC16) | Ceramic 132-Pin PGA 13 × 13 | 16 MHz |
| Device | Position | Package | Speed |
|---|---|---|---|
| A2620 | U202 | PGA | 16 MHz |
| Pin | Type | Name |
|---|---|---|
| A1 | Output | PA23 |
| A2..A3 | Output | PA29..PA30 |
| A4 | Input | _LAS |
| A5 | Output | _LBRO |
| A6 | Input | _LBGI |
| A7 | Input | _LBRI |
| A8 | Output | _CLI |
| A9 | Output | _PBG |
| A10 | Input | _PBGACK |
| A11 | I/O | _DSACK0 |
| A12 | I/O | SIZ1 |
| A13 | Input | _RESET |
| B1 | Output | PA19 |
| B2..B3 | Output | PA25..PA26 |
| B4 | Output | PA28 |
| B5 | Output | _PAS |
| B6 | I/O | _LBGACK |
| B7 | Power | VCC |
| B8 | I/O | _HALT |
| B9 | Input | _PBR |
| B10 | I/O | SIZ0 |
| B11 | I/O | _DS |
| B12 | I/O | _RMC |
| B13 | I/O | D3 |
| C1 | Output | PA18 |
| C2 | Output | PA22 |
| C3 | Input | CLK |
| C4 | Output | PA27 |
| C5 | Output | PA31 |
| C6 | Output | _LBGO |
| C7 | Power | GND |
| C8 | I/O | _BERR |
| C9 | I/O | _DSACK1 |
| C10 | I/O | R/_W |
| C11 | Output | DBDIS |
| C12 | I/O | D0 |
| C13 | I/O | D4 |
| D1 | Output | PA15 |
| D2..D3 | Output | PA20..PA21 |
| D4 | Output | PA24 |
| D5 | Power | VCC |
| D9 | Power | GND |
| D10 | Input | _ASYNC |
| D11..D12 | I/O | D1..D2 |
| D13 | I/O | D7 |
| E1 | Output | PA14 |
| E2..E3 | Output | PA16..PA17 |
| E4 | Power | GND |
| E10 | Power | VCC |
| E11..E12 | I/O | D5..D6 |
| E13 | I/O | D8 |
| F1..F3 | Output | PA11..PA13 |
| F11..F13 | I/O | D9..D11 |
| G1 | Output | PA10 |
| G2 | Power | VCC |
| G3 | Power | GND |
| G11 | Power | GND |
| G12 | Power | VCC |
| G13 | I/O | D12 |
| H1..H3 | Output | PA9..PA7 |
| H11..H13 | I/O | D15..D13 |
| J1 | I/O | A6 |
| J2..J3 | I/O | A4..A3 |
| J4 | Power | VCC |
| J10 | Power | GND |
| J11..J12 | I/O | D19..D18 |
| J13 | I/O | D16 |
| K1 | I/O | A5 |
| K2 | I/O | A0 |
| K3 | I/O | FC3 |
| K4 | I/O | FC0 |
| K5 | Power | GND |
| K9 | Power | VCC |
| K10 | I/O | D26 |
| K11..K12 | I/O | D23..D22 |
| K13 | I/O | D17 |
| L1 | I/O | A2 |
| L2 | I/O | FC2 |
| L3 | Input | LA31 |
| L4 | Input | LA28 |
| L5 | Input | LA24 |
| L6 | Input | LA20 |
| L7 | Power | GND |
| L8 | Input | LA14 |
| L9 | Input | LA10 |
| L10 | I/O | D30 |
| L11 | I/O | D27 |
| L12 | I/O | D24 |
| L13 | I/O | D20 |
| M1 | I/O | A1 |
| M2..M3 | Input | LA30..LA29 |
| M4 | Input | LA27 |
| M5 | Input | LA23 |
| M6 | Input | LA19 |
| M7 | Power | VCC |
| M8 | Input | LA15 |
| M9 | Input | LA11 |
| M10 | I/O | D31 |
| M11..M12 | I/O | D29..D28 |
| M13 | I/O | D21 |
| N1 | I/O | FC1 |
| N2..N3 | Input | LA26..LA25 |
| N4..N5 | Input | LA22..LA21 |
| N6..N8 | Input | LA18..LA16 |
| N9..N10 | Input | LA13..LA12 |
| N11..N12 | Input | LA9..LA8 |
| N13 | I/O | D25 |